draft-ietf-mobileip-ipv6-08.txt   draft-ietf-mobileip-ipv6-09.txt 
IETF Mobile IP Working Group David B. Johnson IETF Mobile IP Working Group David B. Johnson
INTERNET-DRAFT Carnegie Mellon University INTERNET-DRAFT Carnegie Mellon University
Charles Perkins Charles Perkins
Sun Microsystems Nokia
25 June 1999 22 October 1999
Mobility Support in IPv6 Mobility Support in IPv6
<draft-ietf-mobileip-ipv6-08.txt> <draft-ietf-mobileip-ipv6-09.txt>
Status of This Memo Status of This Memo
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC 2026. all provisions of Section 10 of RFC 2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note Task Force (IETF), its areas, and its working groups. Note
that other groups may also distribute working documents as that other groups may also distribute working documents as
Internet-Drafts. Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents, valid for a maximum of six
and may be updated, replaced, or obsoleted by other documents at months, and may be updated, replaced, or obsoleted by other documents
any time. It is inappropriate to use Internet-Drafts as reference at any time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
Abstract Abstract
skipping to change at page 1, line 77 skipping to change at page 1, line 77
4.3. Conceptual Data Structures . . . . . . . . . . . . . . . 13 4.3. Conceptual Data Structures . . . . . . . . . . . . . . . 13
4.4. Binding Management . . . . . . . . . . . . . . . . . . . 17 4.4. Binding Management . . . . . . . . . . . . . . . . . . . 17
5. New IPv6 Destination Options 19 5. New IPv6 Destination Options 19
5.1. Binding Update Option Format . . . . . . . . . . . . . . 19 5.1. Binding Update Option Format . . . . . . . . . . . . . . 19
5.2. Binding Acknowledgement Option Format . . . . . . . . . . 23 5.2. Binding Acknowledgement Option Format . . . . . . . . . . 23
5.3. Binding Request Option Format . . . . . . . . . . . . . . 27 5.3. Binding Request Option Format . . . . . . . . . . . . . . 27
5.4. Home Address Option Format . . . . . . . . . . . . . . . 29 5.4. Home Address Option Format . . . . . . . . . . . . . . . 29
5.5. Mobile IPv6 Destination Option Sub-Options . . . . . . . 31 5.5. Mobile IPv6 Destination Option Sub-Options . . . . . . . 31
6. Modifications to IPv6 Neighbor Discovery 33 6. Modifications to IPv6 Neighbor Discovery 34
6.1. Modified Router Advertisement Message Format . . . . . . 33 6.1. Modified Router Advertisement Message Format . . . . . . 34
6.2. Modified Prefix Information Option Format . . . . . . . . 34 6.2. Modified Prefix Information Option Format . . . . . . . . 36
6.3. New Advertisement Interval Option Format . . . . . . . . 36 6.3. New Advertisement Interval Option Format . . . . . . . . 38
6.4. New Home Agent Information Option Format . . . . . . . . 37 6.4. New Home Agent Information Option Format . . . . . . . . 39
6.5. Changes to Sending Router Advertisements . . . . . . . . 39 6.5. Changes to Sending Router Advertisements . . . . . . . . 41
6.6. Changes to Sending Router Solicitations . . . . . . . . . 40 6.6. Changes to Sending Router Solicitations . . . . . . . . . 42
7. Requirements for IPv6 Nodes 42 7. Requirements for IPv6 Nodes 44
7.1. Requirements for All IPv6 Hosts and Routers . . . . . . . 42 7.1. Requirements for All IPv6 Hosts and Routers . . . . . . . 44
7.2. Requirements for All IPv6 Routers . . . . . . . . . . . . 42 7.2. Requirements for All IPv6 Routers . . . . . . . . . . . . 44
7.3. Requirements for IPv6 Home Agents . . . . . . . . . . . . 42 7.3. Requirements for IPv6 Home Agents . . . . . . . . . . . . 44
7.4. Requirements for IPv6 Mobile Nodes . . . . . . . . . . . 43 7.4. Requirements for IPv6 Mobile Nodes . . . . . . . . . . . 45
8. Correspondent Node Operation 45 8. Correspondent Node Operation 47
8.1. Receiving Packets from a Mobile Node . . . . . . . . . . 45 8.1. Receiving Packets from a Mobile Node . . . . . . . . . . 47
8.2. Receiving Binding Updates . . . . . . . . . . . . . . . . 45 8.2. Receiving Binding Updates . . . . . . . . . . . . . . . . 47
8.3. Requests to Cache a Binding . . . . . . . . . . . . . . . 46 8.3. Requests to Cache a Binding . . . . . . . . . . . . . . . 48
8.4. Requests to Delete a Binding . . . . . . . . . . . . . . 47 8.4. Requests to Delete a Binding . . . . . . . . . . . . . . 49
8.5. Sending Binding Acknowledgements . . . . . . . . . . . . 47 8.5. Sending Binding Acknowledgements . . . . . . . . . . . . 49
8.6. Sending Binding Requests . . . . . . . . . . . . . . . . 48 8.6. Sending Binding Requests . . . . . . . . . . . . . . . . 50
8.7. Cache Replacement Policy . . . . . . . . . . . . . . . . 48 8.7. Cache Replacement Policy . . . . . . . . . . . . . . . . 50
8.8. Receiving ICMP Error Messages . . . . . . . . . . . . . . 49 8.8. Receiving ICMP Error Messages . . . . . . . . . . . . . . 51
8.9. Sending Packets to a Mobile Node . . . . . . . . . . . . 50 8.9. Sending Packets to a Mobile Node . . . . . . . . . . . . 52
9. Home Agent Operation 52 9. Home Agent Operation 54
9.1. Receiving Router Advertisement Messages . . . . . . . . . 52 9.1. Receiving Router Advertisement Messages . . . . . . . . . 54
9.2. Dynamic Home Agent Address Discovery . . . . . . . . . . 53 9.2. Dynamic Home Agent Address Discovery . . . . . . . . . . 55
9.3. Primary Care-of Address Registration . . . . . . . . . . 55 9.3. Primary Care-of Address Registration . . . . . . . . . . 57
9.4. Primary Care-of Address De-registration . . . . . . . . . 57 9.4. Primary Care-of Address De-registration . . . . . . . . . 59
9.5. Intercepting Packets for a Mobile Node . . . . . . . . . 58 9.5. Intercepting Packets for a Mobile Node . . . . . . . . . 60
9.6. Tunneling Intercepted Packets to a Mobile Node . . . . . 60 9.6. Tunneling Intercepted Packets to a Mobile Node . . . . . 62
9.7. Renumbering the Home Subnet . . . . . . . . . . . . . . . 61 9.7. Renumbering the Home Subnet . . . . . . . . . . . . . . . 63
10. Mobile Node Operation 65 10. Mobile Node Operation 67
10.1. Sending Packets While Away from Home . . . . . . . . . . 65 10.1. Sending Packets While Away from Home . . . . . . . . . . 67
10.2. Receiving Packets While Away from Home . . . . . . . . . 67 10.2. Interaction with Outbound IPsec Processing . . . . . . . 68
10.3. Movement Detection . . . . . . . . . . . . . . . . . . . 68 10.3. Receiving Packets While Away from Home . . . . . . . . . 69
10.4. Forming New Care-of Addresses . . . . . . . . . . . . . . 71 10.4. Movement Detection . . . . . . . . . . . . . . . . . . . 71
10.5. Sending Binding Updates to the Home Agent . . . . . . . . 72 10.5. Forming New Care-of Addresses . . . . . . . . . . . . . . 74
10.6. Dynamic Home Agent Address Discovery . . . . . . . . . . 73 10.6. Sending Binding Updates to the Home Agent . . . . . . . . 75
10.7. Sending Binding Updates to Correspondent Nodes . . . . . 74 10.7. Dynamic Home Agent Address Discovery . . . . . . . . . . 76
10.8. Sending Binding Updates to the Previous Default Router . 76 10.8. Sending Binding Updates to Correspondent Nodes . . . . . 76
10.9. Retransmitting Binding Updates . . . . . . . . . . . . . 77 10.9. Establishing Forwarding from a Previous Care-of Address . 79
10.10. Rate Limiting for Sending Binding Updates . . . . . . . . 77 10.10. Retransmitting Binding Updates . . . . . . . . . . . . . 80
10.11. Receiving Binding Acknowledgements . . . . . . . . . . . 77 10.11. Rate Limiting for Sending Binding Updates . . . . . . . . 80
10.12. Receiving Binding Requests . . . . . . . . . . . . . . . 78 10.12. Receiving Binding Acknowledgements . . . . . . . . . . . 81
10.13. Receiving ICMP Error Messages . . . . . . . . . . . . . . 79 10.13. Receiving Binding Requests . . . . . . . . . . . . . . . 82
10.14. Receiving Tunneled Router Advertisements . . . . . . . . 79 10.14. Receiving ICMP Error Messages . . . . . . . . . . . . . . 82
10.15. Using Multiple Care-of Addresses . . . . . . . . . . . . 80 10.15. Receiving Tunneled Router Advertisements . . . . . . . . 83
10.16. Routing Multicast Packets . . . . . . . . . . . . . . . . 81 10.16. Using Multiple Care-of Addresses . . . . . . . . . . . . 84
10.17. Returning Home . . . . . . . . . . . . . . . . . . . . . 82 10.17. Routing Multicast Packets . . . . . . . . . . . . . . . . 84
10.18. Returning Home . . . . . . . . . . . . . . . . . . . . . 85
11. Constants 83 11. Constants 86
12. IANA Considerations 84 12. IANA Considerations 87
13. Security Considerations 85 13. Security Considerations 88
13.1. Binding Updates, Acknowledgements, and Requests . . . . . 85 13.1. Binding Updates, Acknowledgements, and Requests . . . . . 88
13.2. Home Address Option . . . . . . . . . . . . . . . . . . . 85 13.2. Home Address Option . . . . . . . . . . . . . . . . . . . 88
13.3. General Mobile Computing Issues . . . . . . . . . . . . . 86 13.3. General Mobile Computing Issues . . . . . . . . . . . . . 89
Changes from Previous Version of the Draft 88 Changes from Previous Version of the Draft 91
Acknowledgements 90 Acknowledgements 93
References 91 References 94
Chair's Address 93 Chair's Address 96
Authors' Addresses 94 Authors' Addresses 97
1. Introduction 1. Introduction
This document specifies the operation of mobile computers using This document specifies the operation of mobile computers using
Internet Protocol Version 6 (IPv6) [5]. Without specific support Internet Protocol Version 6 (IPv6) [5]. Without specific support
for mobility in IPv6, packets destined to a mobile node (host or for mobility in IPv6, packets destined to a mobile node (host or
router) would not be able to reach it while the mobile node is away router) would not be able to reach it while the mobile node is away
from its home link (the link on which its home IPv6 subnet prefix is from its home link (the link on which its home IPv6 subnet prefix is
in use), since routing is based on the subnet prefix in a packet's in use), since routing is based on the subnet prefix in a packet's
destination IP address. In order to continue communication in spite destination IP address. In order to continue communication in spite
skipping to change at page 2, line 13 skipping to change at page 2, line 13
beyond the scope of this document. beyond the scope of this document.
The protocol specified in this document solves the problem of The protocol specified in this document solves the problem of
transparently routing packets to and from mobile nodes while away transparently routing packets to and from mobile nodes while away
from home. However, it does not attempt to solve all general from home. However, it does not attempt to solve all general
problems related to the use of mobile computers or wireless networks. problems related to the use of mobile computers or wireless networks.
In particular, this protocol does not attempt to solve: In particular, this protocol does not attempt to solve:
- Handling links with partial reachability, such as typical - Handling links with partial reachability, such as typical
wireless networks. Some aspects of this problem are addressed wireless networks. Some aspects of this problem are addressed
by the movement detection procedure described in Section 10.3, by the movement detection procedure described in Section 10.4,
but no attempt has been made to fully solve this problem in its but no attempt has been made to fully solve this problem in its
general form. Most aspects of this problem can be solved by the general form. Most aspects of this problem can be solved by the
workaround of restricting such networks to only one router per workaround of restricting such networks to only one router per
link, although there are still possible hidden terminal problems link, although there are still possible hidden terminal problems
when two nodes on the same link (on opposite sides of the router) when two nodes on the same link (on opposite sides of the router)
attempt to communicate directly. attempt to communicate directly.
- Access control on a link being visited by a mobile node. This - Access control on a link being visited by a mobile node. This
is a general problem any time an untrusted node is allowed is a general problem any time an untrusted node is allowed
to connect to any link layer. It is independent whether the to connect to any link layer. It is independent whether the
skipping to change at page 4, line 12 skipping to change at page 4, line 12
multicast routing that is based in part on the packet's Source multicast routing that is based in part on the packet's Source
Address. Address.
- There is no longer any need to deploy special routers as - There is no longer any need to deploy special routers as
"foreign agents" as are used in Mobile IPv4. In Mobile IPv6, "foreign agents" as are used in Mobile IPv4. In Mobile IPv6,
mobile nodes make use of the enhanced features of IPv6, such mobile nodes make use of the enhanced features of IPv6, such
as Neighbor Discovery [14] and Address Autoconfiguration [23], as Neighbor Discovery [14] and Address Autoconfiguration [23],
to operate in any location away from home without any special to operate in any location away from home without any special
support required from its local router. support required from its local router.
- Unlike Mobile IPv4, Mobile IPv6 utilizes IPsec [9, 10, 11] for - Unlike Mobile IPv4, Mobile IPv6 utilizes IP Security
all security requirements (sender authentication, data integrity (IPsec) [9, 10, 11] for all security requirements (sender
protection, and replay protection) for Binding Updates (which authentication, data integrity protection, and replay protection)
serve the role of both registration and Route Optimization in for Binding Updates (which serve the role of both registration
Mobile IPv4). Mobile IPv4 relies on its own security mechanisms and Route Optimization in Mobile IPv4). Mobile IPv4 relies
for these functions, based on statically configured "mobility on its own security mechanisms for these functions, based on
security associations". statically configured "mobility security associations".
- The movement detection mechanism in Mobile IPv6 provides - The movement detection mechanism in Mobile IPv6 provides
bidirectional confirmation of a mobile node's ability to bidirectional confirmation of a mobile node's ability to
communicate with its default router in its current location communicate with its default router in its current location
(packets that the router sends are reaching the mobile node, and (packets that the router sends are reaching the mobile node, and
packets that the mobile node sends are reaching the router). packets that the mobile node sends are reaching the router).
This confirmation provides a detection of the "black hole" This confirmation provides a detection of the "black hole"
situation that may exist in some wireless environments where the situation that may exist in some wireless environments where the
link to the router does not work equally well in both directions, link to the router does not work equally well in both directions,
such as when the mobile node has moved out of good wireless such as when the mobile node has moved out of good wireless
skipping to change at page 10, line 7 skipping to change at page 10, line 7
care-of address in this binding registered with its home agent is care-of address in this binding registered with its home agent is
known as the mobile node's "primary care-of address". The mobile known as the mobile node's "primary care-of address". The mobile
node's home agent thereafter uses proxy Neighbor Discovery to node's home agent thereafter uses proxy Neighbor Discovery to
intercept any IPv6 packets addressed to the mobile node's home intercept any IPv6 packets addressed to the mobile node's home
address (or home addresses) on the home link, and tunnels each address (or home addresses) on the home link, and tunnels each
intercepted packet to the mobile node's primary care-of address. intercepted packet to the mobile node's primary care-of address.
To tunnel each intercepted packet, the home agent encapsulates the To tunnel each intercepted packet, the home agent encapsulates the
packet using IPv6 encapsulation [4], with the outer IPv6 header packet using IPv6 encapsulation [4], with the outer IPv6 header
addressed to the mobile node's primary care-of address. addressed to the mobile node's primary care-of address.
Section 10.15 discusses the reasons why it may be desirable for Section 10.16 discusses the reasons why it may be desirable for
a mobile node to use more than one care-of address at the same a mobile node to use more than one care-of address at the same
time. However, a mobile node's primary care-of address is distinct time. However, a mobile node's primary care-of address is distinct
among these in that the home agent maintains only a single care-of among these in that the home agent maintains only a single care-of
address registered for each mobile node, and always tunnels a mobile address registered for each mobile node, and always tunnels a mobile
node's packets intercepted from its home link to this mobile node's node's packets intercepted from its home link to this mobile node's
registered primary care-of address. The home agent thus need not registered primary care-of address. The home agent thus need not
implement any policy to determine which of possibly many care-of implement any policy to determine which of possibly many care-of
addresses to which to tunnel each intercepted packet, leaving the addresses to which to tunnel each intercepted packet, leaving the
mobile node entirely in control of this policy by which of its mobile node entirely in control of this policy by which of its
care-of addresses it registers with its home agent. care-of addresses it registers with its home agent.
skipping to change at page 15, line 12 skipping to change at page 15, line 12
- The IP address of the node to which a Binding Update was - The IP address of the node to which a Binding Update was
sent. This node might still have a Binding Cache entry sent. This node might still have a Binding Cache entry
created or updated from this Binding Update, if the Binding created or updated from this Binding Update, if the Binding
Update was successfully received by that node (e.g., not Update was successfully received by that node (e.g., not
lost by the network) and if that node has not deleted the lost by the network) and if that node has not deleted the
entry before its expiration (e.g., to reclaim space in its entry before its expiration (e.g., to reclaim space in its
Binding Cache for other entries). Binding Cache for other entries).
- The home address for which that Binding Update was sent. - The home address for which that Binding Update was sent.
This will be one of the mobile node's home addresses for This will be one of the mobile node's home addresses for
most Binding Updates (Sections 10.5 and 10.7), but will most Binding Updates (Sections 10.6 and 10.8), but will
be the mobile node's previous care-of address for Binding be the mobile node's previous care-of address for Binding
Updates sent to the mobile node's previous default router Updates sent to the mobile node's previous default router
(Section 10.8). (Section 10.9).
- The care-of address sent in that Binding Update. This - The care-of address sent in that Binding Update. This
value is necessary for the mobile node to determine if it value is necessary for the mobile node to determine if it
has sent a Binding Update giving its new care-of address to has sent a Binding Update giving its new care-of address to
this destination after changing its care-of address. this destination after changing its care-of address.
- The remaining lifetime of that binding. This lifetime is - The remaining lifetime of that binding. This lifetime is
initialized from the Lifetime value sent in the Binding initialized from the Lifetime value sent in the Binding
Update and is decremented until it reaches zero, at which Update and is decremented until it reaches zero, at which
time this entry MUST be deleted from the Binding Update time this entry MUST be deleted from the Binding Update
skipping to change at page 15, line 49 skipping to change at page 15, line 49
Update. This state includes the time remaining until the Update. This state includes the time remaining until the
next retransmission attempt for the Binding Update, and the next retransmission attempt for the Binding Update, and the
current state of the exponential back-off mechanism for current state of the exponential back-off mechanism for
retransmissions. retransmissions.
- A flag that, when set, indicates that future Binding - A flag that, when set, indicates that future Binding
Updates should not be sent to this destination. The Updates should not be sent to this destination. The
mobile node sets this flag in the Binding Update List mobile node sets this flag in the Binding Update List
entry when it receives an ICMP Parameter Problem, Code 2, entry when it receives an ICMP Parameter Problem, Code 2,
error message in response to a Binding Update sent to that error message in response to a Binding Update sent to that
destination, as described in Section 10.13. destination, as described in Section 10.14.
Home Agents List Home Agents List
A list, maintained by each home agent, recording information A list, maintained by each home agent, recording information
about each other home agent on a link on which this node about each other home agent on a link on which this node
is serving as a home agent; each home agent maintains a is serving as a home agent; each home agent maintains a
separate Home Agents List for each such link on which it is separate Home Agents List for each such link on which it is
serving. This list is used in the dynamic home agent address serving. This list is used in the dynamic home agent address
discovery mechanism. The information for the list is learned discovery mechanism. The information for the list is learned
through receipt of the periodic unsolicited multicast Router through receipt of the periodic unsolicited multicast Router
skipping to change at page 19, line 24 skipping to change at page 19, line 24
packet sent by a mobile node (Section 10.1). packet sent by a mobile node (Section 10.1).
The Binding Update option is encoded in type-length-value (TLV) The Binding Update option is encoded in type-length-value (TLV)
format as follows: format as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Type | Option Length | | Option Type | Option Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|H|C|R|Reservd| Prefix Length | Sequence Number | |A|H|R| Reserved| Prefix Length | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lifetime | | Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Care-of Address +
| (only present if C bit set) |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Options... | Sub-Options...
+-+-+-+-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+-+-+-+-
Option Type Option Type
198 = 0xC6 198 = 0xC6
Option Length Option Length
8-bit unsigned integer. Length of the option, in octets, 8-bit unsigned integer. Length of the option, in octets,
excluding the Option Type and Option Length fields. This field excluding the Option Type and Option Length fields. This field
MUST be set to 8 (or to 24 if the Care-of Address Present (C) MUST be set to 8 plus the total length of all sub-options
bit is set), plus the total length of all sub-options present, present, including their Sub-Option Type and Sub-Option Len
including their Sub-Option Type and Sub-Option Len fields. fields.
Acknowledge (A) Acknowledge (A)
The Acknowledge (A) bit is set by the sending mobile node to The Acknowledge (A) bit is set by the sending mobile node to
request a Binding Acknowledgement (Section 5.2) be returned request a Binding Acknowledgement (Section 5.2) be returned
upon receipt of the Binding Update. upon receipt of the Binding Update.
Home Registration (H) Home Registration (H)
The Home Registration (H) bit is set by the sending mobile node The Home Registration (H) bit is set by the sending mobile node
to request the receiving node to act as this node's home agent. to request the receiving node to act as this node's home agent.
The destination of the packet carrying this option MUST be that The destination of the packet carrying this option MUST be that
of a router sharing the same subnet prefix as the home address of a router sharing the same subnet prefix as the home address
of the mobile node in the binding (given by the Home Address of the mobile node in the binding (given by the Home Address
field in the Home Address option in the packet). field in the Home Address option in the packet).
Care-of Address Present (C)
The Care-of Address Present (C) bit, when set, indicates the
presence of the Care-of Address field in the Binding Update.
The care-of address for this binding is either the address in
the Care-of Address field in the Binding Update, if this bit is
set, or the Source Address in the packet's IPv6 header, if this
bit is not set.
Router (R) Router (R)
The Router (R) bit, when set, indicates that the sending The Router (R) bit, when set, indicates that the sending
mobile node is a router. This bit is only valid when the mobile node is a router. This bit is only valid when the
Home Registration (H) bit is also set, and MUST NOT be set Home Registration (H) bit is also set, and MUST NOT be set
otherwise. This bit is saved in the home agent's "home otherwise. This bit is saved in the home agent's "home
registration" Binding Cache entry for the mobile node, and registration" Binding Cache entry for the mobile node, and
is copied into the corresponding bit in all proxy Neighbor is copied into the corresponding bit in all proxy Neighbor
Advertisement messages sent on behalf of this mobile node by Advertisement messages sent on behalf of this mobile node by
the home agent using this Binding Cache entry. the home agent using this Binding Cache entry.
Reservd Reserved
Reserved. Sent as 0; ignored on reception. Reserved. Sent as 0; ignored on reception.
Prefix Length Prefix Length
The Prefix Length field is valid only for a "home registration" The Prefix Length field is valid only for a "home registration"
Binding Update. This field MUST be zero if the Home Binding Update. This field MUST be zero if the Home
Registration (H) bit is not set in the Binding Update. The Registration (H) bit is not set in the Binding Update. The
Prefix Length field is set by the sending mobile node to the Prefix Length field is set by the sending mobile node to the
(nonzero) length of its subnet prefix in its home address (nonzero) length of its subnet prefix in its home address
skipping to change at page 21, line 24 skipping to change at page 20, line 53
Duplicate Address Detection. Details of this operation are Duplicate Address Detection. Details of this operation are
described in Section 9.3. described in Section 9.3.
Sequence Number Sequence Number
Used by the receiving node to sequence Binding Updates and by Used by the receiving node to sequence Binding Updates and by
the sending node to match a returned Binding Acknowledgement the sending node to match a returned Binding Acknowledgement
with this Binding Update. Each Binding Update sent by a mobile with this Binding Update. Each Binding Update sent by a mobile
node MUST use a Sequence Number greater than the Sequence node MUST use a Sequence Number greater than the Sequence
Number value sent in the previous Binding Update (if any) to Number value sent in the previous Binding Update (if any) to
the same destination address (modulo 2**16). the same destination address (modulo 2**16). There is no
requirement, however, that the Sequence Number value strictly
increase by 1 with each new Binding Update sent or received.
Lifetime Lifetime
32-bit unsigned integer. The number of seconds remaining 32-bit unsigned integer. The number of seconds remaining
before the binding must be considered expired. A value of all before the binding must be considered expired. A value of all
one bits (0xffffffff) indicates infinity. A value of zero one bits (0xffffffff) indicates infinity. A value of zero
indicates that the Binding Cache entry for the mobile node indicates that the Binding Cache entry for the mobile node
should be deleted. should be deleted.
Care-of Address
This field in the Binding Update is optional and is only
present when the Care-of Address Present (C) bit is set. If
present, it gives the care-of address of the mobile node for
this binding. For most Binding Updates sent, it is expected
that this field will not be present, and instead that the
care-of address for the binding will be given by the Source
Address field in the packet's IPv6 header.
Sub-Options Sub-Options
Additional information, associated with this Binding Update Additional information, associated with this Binding Update
option, that need not be present in all Binding Updates sent. option, that need not be present in all Binding Updates sent.
This use of sub-options also allows for future extensions to This use of sub-options also allows for future extensions to
the format of the Binding Update option to be defined. The the format of the Binding Update option to be defined. The
encoding and format of defined sub-options are described in encoding and format of defined sub-options are described in
Section 5.5. The following sub-options are valid in a Binding Section 5.5. The following sub-options are valid in a Binding
Update option: Update option:
- Unique Identifier Sub-Option - Unique Identifier Sub-Option
- Alternate Care-of Address Sub-Option
The alignment requirement [5] for the Binding Update option is 4n+2.
Any packet that includes a Binding Update option MUST also include Any packet that includes a Binding Update option MUST also include
a Home Address option. The home address of the mobile node in the a Home Address option. The home address of the mobile node in the
binding given in the Binding Update option is indicated by the Home binding given in the Binding Update option is indicated by the Home
Address field in the Home Address option in the packet. Address field in the Home Address option in the packet.
The care-of address for the binding given in the Binding Update
option is normally specified by the Source Address field in the IPv6
header of the packet carrying the Binding Update option. However, a
care-of address different from the Source Address MAY be specified
by including an Alternate Care-of Address sub-option in the Binding
Update option.
Any packet that includes a Binding Update option MUST also include Any packet that includes a Binding Update option MUST also include
either an AH [9] or ESP [10] header providing sender authentication, either an AH [9] or ESP [10] header providing sender authentication,
data integrity protection, and replay protection. data integrity protection, and replay protection.
If the care-of address in the binding (either the Care-of Address If the care-of address for the binding (specified either in an
field in the Binding Update option or the Source Address field in Alternate Care-of Address sub-option in the Binding Update option, if
the packet's IPv6 header) is equal to the home address of the mobile present, or in the Source Address field in the packet's IPv6 header)
node, the Binding Update option indicates that any existing binding is equal to the home address of the mobile node, the Binding Update
for the mobile node MUST be deleted. Likewise, if the Lifetime
field in the Binding Update option is equal to 0, the Binding Update
option indicates that any existing binding for the mobile node MUST option indicates that any existing binding for the mobile node MUST
be deleted. In each of these cases, a Binding Cache entry for the be deleted. Likewise, if the Lifetime field in the Binding Update
mobile node MUST NOT be created in response to receiving the Binding option is equal to 0, the Binding Update option indicates that any
Update. existing binding for the mobile node MUST be deleted. In each of
these cases, a Binding Cache entry for the mobile node MUST NOT be
created in response to receiving the Binding Update.
The last Sequence Number value sent to a destination in a Binding The last Sequence Number value sent to a destination in a Binding
Update is stored by the mobile node in its Binding Update List entry Update is stored by the mobile node in its Binding Update List entry
for that destination; the last Sequence Number value received from for that destination; the last Sequence Number value received from
a mobile node in a Binding Update is stored by a correspondent node a mobile node in a Binding Update is stored by a correspondent node
in its Binding Cache entry for that mobile node. Thus, the mobile in its Binding Cache entry for that mobile node. Thus, the mobile
node's and the correspondent node's knowledge of the last sequence node's and the correspondent node's knowledge of the last sequence
number expire at the same time. If the sending mobile node has no number expire at the same time. If the sending mobile node has no
Binding Update List entry, the Sequence Number may start at any Binding Update List entry, the Sequence Number may start at any
value; if the receiving correspondent node has no Binding Cache entry value; if the receiving correspondent node has no Binding Cache entry
skipping to change at page 24, line 14 skipping to change at page 24, line 14
indicate that the Binding Update was accepted by the receiving indicate that the Binding Update was accepted by the receiving
node. The following such Status values are currently defined: node. The following such Status values are currently defined:
0 Binding Update accepted 0 Binding Update accepted
Values of the Status field greater than or equal to 128 Values of the Status field greater than or equal to 128
indicate that the Binding Update was rejected by the receiving indicate that the Binding Update was rejected by the receiving
node. The following such Status values are currently defined: node. The following such Status values are currently defined:
128 Reason unspecified 128 Reason unspecified
129 Poorly formed Binding Update
130 Administratively prohibited 130 Administratively prohibited
131 Insufficient resources 131 Insufficient resources
132 Home registration not supported 132 Home registration not supported
133 Not home subnet 133 Not home subnet
134 Sequence Number field value too small
135 Dynamic home agent address discovery response 135 Dynamic home agent address discovery response
136 Incorrect interface identifier length 136 Incorrect interface identifier length
137 Not home agent for this mobile node 137 Not home agent for this mobile node
Up-to-date values of the Status field are to be specified in Up-to-date values of the Status field are to be specified in
the most recent "Assigned Numbers" [22]. the most recent "Assigned Numbers" [22].
Sequence Number Sequence Number
The Sequence Number in the Binding Acknowledgement is copied The Sequence Number in the Binding Acknowledgement is copied
from the Sequence Number field in the Binding Update being from the Sequence Number field in the Binding Update being
acknowledged, for use by the mobile node in matching this acknowledged, for use by the mobile node in matching this
Acknowledgement with an outstanding Binding Update. Acknowledgement with an outstanding Binding Update.
Lifetime Lifetime
The granted lifetime for which this node will attempt to retain The granted lifetime, in seconds, for which this node will
the entry for this mobile node in its Binding Cache. If the attempt to retain the entry for this mobile node in its Binding
node sending the Binding Acknowledgement is serving as the Cache. If the node sending the Binding Acknowledgement is
mobile node's home agent, the Lifetime period also indicates serving as the mobile node's home agent, the Lifetime period
the period for which this node will continue this service; if also indicates the period for which this node will continue
the mobile node requires home agent service from this node this service; if the mobile node requires home agent service
beyond this period, the mobile node MUST send a new Binding from this node beyond this period, the mobile node MUST send a
Update to it before the expiration of this period (even if new Binding Update to it before the expiration of this period
it is not changing its primary care-of address), in order to (even if it is not changing its primary care-of address), in
extend the lifetime. The value of this field is undefined order to extend the lifetime. The value of this field is
if the Status field indicates that the Binding Update was undefined if the Status field indicates that the Binding Update
rejected. was rejected.
Refresh Refresh
The recommended interval at which the mobile node SHOULD send The recommended interval, in seconds, at which the mobile
a new Binding Update to this node in order to "refresh" the node SHOULD send a new Binding Update to this node in order
mobile node's binding in this node's Binding Cache. This to "refresh" the mobile node's binding in this node's Binding
refreshing of the binding is useful in case the node fails and Cache. This refreshing of the binding is useful in case the
loses its cache state. The Refresh period is determined by node fails and loses its cache state. The Refresh period is
the node sending the Binding Acknowledgement (the node caching determined by the node sending the Binding Acknowledgement
the binding). If this node is serving as the mobile node's (the node caching the binding). If this node is serving as
home agent, the Refresh value may be set, for example, based on the mobile node's home agent, the Refresh value may be set,
whether the node stores its Binding Cache in volatile storage for example, based on whether the node stores its Binding
or in nonvolatile storage. If the node sending the Binding Cache in volatile storage or in nonvolatile storage. If the
Acknowledgement is not serving as the mobile node's home agent, node sending the Binding Acknowledgement is not serving as the
the Refresh period SHOULD be set equal to the Lifetime period mobile node's home agent, the Refresh period SHOULD be set
in the Binding Acknowledgement; even if this node loses this equal to the Lifetime period in the Binding Acknowledgement;
cache entry due to a failure of the node, packets from it can even if this node loses this cache entry due to a failure of
still reach the mobile node through the mobile node's home the node, packets from it can still reach the mobile node
agent, causing a new Binding Update to this node to allow it through the mobile node's home agent, causing a new Binding
to recreate this cache entry. The value of this field is Update to this node to allow it to recreate this cache entry.
undefined if the Status field indicates that the Binding Update The value of this field is undefined if the Status field
was rejected. indicates that the Binding Update was rejected.
Sub-Options Sub-Options
Additional information, associated with this Binding Additional information, associated with this Binding
Acknowledgement option, that need not be present in all Binding Acknowledgement option, that need not be present in all Binding
Acknowledgements sent. This use of sub-options also allows for Acknowledgements sent. This use of sub-options also allows for
future extensions to the format of the Binding Acknowledgement future extensions to the format of the Binding Acknowledgement
option to be defined. The encoding and format of defined option to be defined. The encoding and format of defined
sub-options are described in Section 5.5. The following sub-options are described in Section 5.5. The following
sub-options are valid in a Binding Acknowledgement option: sub-options are valid in a Binding Acknowledgement option:
- Home Agents List Sub-Option - Home Agents List Sub-Option
The alignment requirement [5] for the Binding Acknowledgement option
is 4n+3.
Any packet that includes a Binding Acknowledgement option MUST Any packet that includes a Binding Acknowledgement option MUST
also include either an AH [9] or ESP [10] header providing sender also include either an AH [9] or ESP [10] header providing sender
authentication, data integrity protection, and replay protection. authentication, data integrity protection, and replay protection.
If the node returning the Binding Acknowledgement accepted the If the node returning the Binding Acknowledgement accepted the
Binding Update for which the Acknowledgement is being returned (the Binding Update for which the Acknowledgement is being returned (the
value of the Status field in the Acknowledgement is less than 128), value of the Status field in the Acknowledgement is less than 128),
this node will have an entry for the mobile node in its Binding Cache this node will have an entry for the mobile node in its Binding Cache
and MUST use this entry (which includes the care-of address received and MUST use this entry (which includes the care-of address received
in the Binding Update) in sending the packet containing the Binding in the Binding Update) in sending the packet containing the Binding
skipping to change at page 27, line 49 skipping to change at page 27, line 49
Additional information, associated with this Binding Request Additional information, associated with this Binding Request
option, that need not be present in all Binding Requests sent. option, that need not be present in all Binding Requests sent.
This use of sub-options also allows for future extensions to This use of sub-options also allows for future extensions to
the format of the Binding Request option to be defined. The the format of the Binding Request option to be defined. The
encoding and format of defined sub-options are described in encoding and format of defined sub-options are described in
Section 5.5. The following sub-options are valid in a Binding Section 5.5. The following sub-options are valid in a Binding
Request option: Request option:
- Unique Identifier Sub-Option - Unique Identifier Sub-Option
There is no requirement for alignment [5] of the Binding Request
option.
The three highest-order bits of the Option Type are encoded to The three highest-order bits of the Option Type are encoded to
indicate specific processing of the option [5]. For the Binding indicate specific processing of the option [5]. For the Binding
Request option, these three bits are set to 000, indicating that any Request option, these three bits are set to 000, indicating that any
IPv6 node processing this option that does not recognize the Option IPv6 node processing this option that does not recognize the Option
Type must skip over this option and continue processing the header, Type must skip over this option and continue processing the header,
and that the data within the option cannot change en-route to the and that the data within the option cannot change en-route to the
packet's final destination. packet's final destination.
5.4. Home Address Option Format 5.4. Home Address Option Format
skipping to change at page 30, line 15 skipping to change at page 30, line 15
Sub-Options Sub-Options
Additional information, associated with this Home Address Additional information, associated with this Home Address
option, that need not be present in all Home Address options option, that need not be present in all Home Address options
sent. This use of sub-options also allows for future sent. This use of sub-options also allows for future
extensions to the format of the Home Address option to be extensions to the format of the Home Address option to be
defined. The encoding and format of defined sub-options are defined. The encoding and format of defined sub-options are
described in Section 5.5. Currently, no valid sub-options are described in Section 5.5. Currently, no valid sub-options are
defined for use in a Home Address option. defined for use in a Home Address option.
The alignment requirement [5] for the Home Address option is 8n+6.
The inclusion of a Home Address option in a packet affects the The inclusion of a Home Address option in a packet affects the
receiving node's processing of only this single packet; no state is receiving node's processing of only this single packet; no state is
created or modified in the receiving node as a result of receiving a created or modified in the receiving node as a result of receiving a
Home Address option in a packet. In particular, the presence of a Home Address option in a packet. In particular, the presence of a
Home Address option in a received packet MUST NOT alter the contents Home Address option in a received packet MUST NOT alter the contents
of the receiver's Binding Cache and MUST NOT cause any changes in the of the receiver's Binding Cache and MUST NOT cause any changes in the
routing of subsequent packets sent by this receiving node. routing of subsequent packets sent by this receiving node.
No authentication of the Home Address option is required, except that No authentication of the Home Address option is required, except that
if the IPv6 header of a packet is covered by authentication, then if the IPv6 header of a packet is covered by authentication, then
skipping to change at page 31, line 51 skipping to change at page 31, line 51
8-bit unsigned integer. Length of the Sub-Option Data field 8-bit unsigned integer. Length of the Sub-Option Data field
of this sub-option, in octets. The Sub-Option Len does not of this sub-option, in octets. The Sub-Option Len does not
include the length of the Sub-Option Type and Sub-Option Len include the length of the Sub-Option Type and Sub-Option Len
fields. fields.
Sub-Option Data Sub-Option Data
Variable-length field. Sub-Option-Type-specific data. Variable-length field. Sub-Option-Type-specific data.
As with IPv6 options appearing in a Hop-by-Hop Options header
or Destination Options header [5], individual sub-options within
a Mobile IPv6 destination option may have specific alignment
requirements, to ensure that multi-octet values within Sub-Option
Data fields fall on natural boundaries. The alignment requirement
of a sub-option is specified using the same notation as is used to
specify alignment requirements for IPv6 options [5].
Each section above defining the Mobile IPv6 destination options Each section above defining the Mobile IPv6 destination options
specifies which of the defined sub-options is valid for that specifies which of the defined sub-options is valid for that
destination option. destination option. In addition, there are two padding sub-options,
Pad1 and PadN (defined below), which are used when necessary to align
subsequent sub-options. The Pad1 and PadN sub-options are valid for
all Mobile IPv6 destination options. Unlike the padding options
used in Hop-by-Hop Options header or Destination Options header [5],
there is no requirement for padding the total size of any Mobile IPv6
destination option to a multiple of 8 octets in length, and the
Pad1 and PadN sub-options SHOULD NOT be used for this purpose. All
Mobile IPv6 sub-options defined in this document MUST be recognized
by all Mobile IPv6 implementations.
Currently, the following two sub-option types are defined for use in Currently, the following sub-option types are defined for use in
Mobile IPv6 destination options: Mobile IPv6 destination options:
Unique Identifier Sub-Option Pad1 Sub-Option (alignment requirement: none)
This sub-option is valid only in Binding Request and Binding 0
Update destination options. The Sub-Option Data contains a 0 1 2 3 4 5 6 7
single 16-bit value that serves to uniquely identify a Binding +-+-+-+-+-+-+-+-+
Request among those sent by this Source Address, and to allow | 0 |
the Binding Update to identify the specific Binding Request to +-+-+-+-+-+-+-+-+
which it responds. This matching of Binding Updates to Binding
Requests is required in the procedure for renumbering the home
subnet while a mobile node is away from home (Section 9.7).
The Sub-Option Type and Sub-Option Len fields for this
sub-option MUST be set as follows:
- Sub-Option Type: 1 NOTE! the format of the Pad1 sub-option is a special
case -- it does not have Sub-Option Len and Sub-Option Data
fields.
- Sub-Option Len: 2 The Pad1 sub-option is used to insert one octet of padding
into the Sub-Options area of a Mobile IPv6 option. If more
than one octet of padding is required, the PadN sub-option,
described next, should be used, rather than multiple Pad1
sub-options.
Home Agents List Sub-Option PadN Sub-Option (alignment requirement: none)
This sub-option is valid only in a Binding Acknowledgement 0 1
destination option. The Sub-Option Data contains a list of 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
home agents on the home link for the mobile node to which +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
this Binding Acknowledgement is sent. This sub-option MUST | 1 | Sub-Option Len| Sub-Option Data
NOT be present unless the Binding Acknowledgement is sent +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
in response to a "Mobile IPv6 Home-Agents" anycast Binding
The PadN sub-option is used to insert two or more octets of
padding into the Sub-Options area of a Mobile IPv6 option.
For N octets of padding, the Sub-Option Len field contains
the value N-2, and the Sub-Option Data consists of N-2
zero-valued octets.
Unique Identifier Sub-Option (alignment requirement: 2n)
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 2 | 2 | Unique Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Unique Identifier sub-option is valid only in Binding
Request and Binding Update destination options. The Unique
Identifier field contains a 16-bit value that serves to
uniquely identify a Binding Request among those sent by this
Source Address, and to allow the Binding Update to identify
the specific Binding Request to which it responds. This
matching of Binding Updates to Binding Requests is required
in the procedure for renumbering the home subnet while a
mobile node is away from home (Section 9.7).
Home Agents List Sub-Option (alignment requirement: 8n+6)
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 3 | 16 * N |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
. Home Agent Addresses .
. (N = number of addresses present) .
. .
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Home Agents List sub-option is valid only in a Binding
Acknowledgement destination option. The Home Agents
Addresses field contains a list of N addresses of home
agents on the home link for the mobile node to which this
Binding Acknowledgement is sent. This sub-option MUST NOT
be present unless the Binding Acknowledgement is sent in
response to a "Mobile IPv6 Home-Agents" anycast Binding
Update sent by a mobile node attempting dynamic home agent Update sent by a mobile node attempting dynamic home agent
address discovery [8]. In this case, the Status field in the address discovery [8]. In this case, the Status field in
Binding Acknowledgement MUST be set to 135 (dynamic home agent the Binding Acknowledgement MUST be set to 135 (dynamic
address discovery response). The specific construction of home agent address discovery response). The specific
the Sub-Option Data field for this sub-option is defined in construction of the Home Agent Addresses field for this
Section 9.2. The Sub-Option Type and Sub-Option Len fields for sub-option is defined in Section 9.2.
this sub-option MUST be set as follows:
- Sub-Option Type: 2 Alternate Care-of Address Sub-Option (alignment requirement: 8n+6)
- Sub-Option Len: 16 * N, where N is the number of home 0 1 2 3
agent addresses included in the Sub-Option Data. 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4 | 16 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Alternate Care-of Addresses |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Alternate Care-of Address sub-option is valid only in
Binding Update destination options. The Alternate Care-of
Address field contains an address to use as the care-of
address for the binding, rather than using the Source
Address of the packet as the care-of address.
6. Modifications to IPv6 Neighbor Discovery 6. Modifications to IPv6 Neighbor Discovery
6.1. Modified Router Advertisement Message Format 6.1. Modified Router Advertisement Message Format
Mobile IPv6 modifies the format of the Router Advertisement Mobile IPv6 modifies the format of the Router Advertisement
message [14] by the addition of a single flag bit for use in the message [14] by the addition of a single flag bit for use in the
dynamic home agent address discovery mechanism (Sections 9.2 dynamic home agent address discovery mechanism (Sections 9.2
and 10.6). The format of the Router Advertisement message is and 10.7). The format of the Router Advertisement message is
as follows: as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum | | Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cur Hop Limit |M|O|H| Reserved| Router Lifetime | | Cur Hop Limit |M|O|H| Reserved| Router Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reachable Time | | Reachable Time |
skipping to change at page 34, line 14 skipping to change at page 36, line 14
6.2. Modified Prefix Information Option Format 6.2. Modified Prefix Information Option Format
Mobile IPv6 requires knowledge of a router's global address for two Mobile IPv6 requires knowledge of a router's global address for two
reasons: reasons:
- To allow a home agent (a router) to learn the address of all - To allow a home agent (a router) to learn the address of all
other home agents on the link for which it is providing home other home agents on the link for which it is providing home
agent service, for use in building its Home Agents List as agent service, for use in building its Home Agents List as
part of the dynamic home agent address discovery mechanism part of the dynamic home agent address discovery mechanism
(Sections 9.2 and 10.6). (Sections 9.2 and 10.7).
- To allow a mobile node to send a Binding Update to its previous - To allow a mobile node to send a Binding Update to its previous
default router, after moving to a new subnet and acquiring a new default router, after moving to a new subnet and acquiring a new
care-of address (Section 10.8). care-of address (Section 10.9).
However, Neighbor Discovery [14] only advertises a router's However, Neighbor Discovery [14] only advertises a router's
link-local address, by requiring this address to be used as the IP link-local address, by requiring this address to be used as the IP
Source Address of each Router Advertisement. Source Address of each Router Advertisement.
Mobile IPv6 extends Neighbor Discovery to allow a router to easily Mobile IPv6 extends Neighbor Discovery to allow a router to easily
and efficiently advertise its global address, by the addition of a and efficiently advertise its global address, by the addition of a
single flag bit in the format of a Prefix Information option for single flag bit in the format of a Prefix Information option for
use in Router Advertisement messages. The format of the Prefix use in Router Advertisement messages. The format of the Prefix
Information option is as follows: Information option is as follows:
skipping to change at page 35, line 34 skipping to change at page 37, line 34
In a solicited Router Advertisement, a router MUST include at least In a solicited Router Advertisement, a router MUST include at least
one Prefix Information option with the Router Address (R) bit set. one Prefix Information option with the Router Address (R) bit set.
Neighbor Discovery specifies that, if including all options in a Neighbor Discovery specifies that, if including all options in a
Router Advertisement causes the size of the Advertisement to exceed Router Advertisement causes the size of the Advertisement to exceed
the link MTU, multiple Advertisements can be sent, each containing the link MTU, multiple Advertisements can be sent, each containing
a subset of the options [14]. In this case, at least one of these a subset of the options [14]. In this case, at least one of these
multiple Advertisements being sent instead of a single larger multiple Advertisements being sent instead of a single larger
solicited Advertisement, MUST include a Prefix Information option solicited Advertisement, MUST include a Prefix Information option
with the Router Address (R) bit set. with the Router Address (R) bit set.
All routers SHOULD include at least on Prefix Information option with All routers SHOULD include at least one Prefix Information option
the Router Address (R) bit set, in each unsolicited multicast Router with the Router Address (R) bit set, in each unsolicited multicast
Advertisement that they send. If multiple Advertisements are being Router Advertisement that they send. If multiple Advertisements
sent instead of a single larger unsolicited multicast Advertisement, are being sent instead of a single larger unsolicited multicast
at least one of these multiple Advertisements SHOULD include a Prefix Advertisement, at least one of these multiple Advertisements SHOULD
Information option with the Router Address (R) bit set. include a Prefix Information option with the Router Address (R) bit
set.
6.3. New Advertisement Interval Option Format 6.3. New Advertisement Interval Option Format
Mobile IPv6 defines a new Advertisement Interval option, used in Mobile IPv6 defines a new Advertisement Interval option, used in
Router Advertisement messages to advertise the interval at which the Router Advertisement messages to advertise the interval at which the
sending router sends unsolicited multicast Router Advertisements. sending router sends unsolicited multicast Router Advertisements.
The format of the Advertisement Interval option is as follows: The format of the Advertisement Interval option is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
skipping to change at page 36, line 47 skipping to change at page 38, line 47
32-bit unsigned integer. The maximum time, in milliseconds, 32-bit unsigned integer. The maximum time, in milliseconds,
between successive unsolicited router Router Advertisement between successive unsolicited router Router Advertisement
messages sent by this router on this network interface. Using messages sent by this router on this network interface. Using
the conceptual router configuration variables defined by the conceptual router configuration variables defined by
Neighbor Discovery [14], this field MUST be equal to the value Neighbor Discovery [14], this field MUST be equal to the value
MaxRtrAdvInterval, expressed in milliseconds. MaxRtrAdvInterval, expressed in milliseconds.
Routers MAY include this option in their Router Advertisements. A Routers MAY include this option in their Router Advertisements. A
mobile node receiving a Router Advertisement containing this option mobile node receiving a Router Advertisement containing this option
SHOULD utilize the specified Advertisement Interval for that router SHOULD utilize the specified Advertisement Interval for that router
in its movement detection algorithm, as described in Section 10.3. in its movement detection algorithm, as described in Section 10.4.
This option MUST be silently ignored for other Neighbor Discovery This option MUST be silently ignored for other Neighbor Discovery
messages. messages.
6.4. New Home Agent Information Option Format 6.4. New Home Agent Information Option Format
Mobile IPv6 defines a new Home Agent Information option, used in Mobile IPv6 defines a new Home Agent Information option, used in
Router Advertisement messages sent by a home agent to advertise Router Advertisement messages sent by a home agent to advertise
information specific to this router's functionality as a home agent. information specific to this router's functionality as a home agent.
The format of the Home Agent Information option is as follows: The format of the Home Agent Information option is as follows:
skipping to change at page 41, line 7 skipping to change at page 43, line 7
address, a mobile node MUST NOT increase the rate at which it address, a mobile node MUST NOT increase the rate at which it
sends Router Solicitations unless it has received a positive sends Router Solicitations unless it has received a positive
indication (such as from lower network layers) that it has moved indication (such as from lower network layers) that it has moved
to a new link. After successfully acquiring a new care-of to a new link. After successfully acquiring a new care-of
address, the mobile node SHOULD also increase the rate at which address, the mobile node SHOULD also increase the rate at which
it will send Router Solicitations when it next begins searching it will send Router Solicitations when it next begins searching
for a new default router and care-of address. for a new default router and care-of address.
- A mobile node that is currently configured with a care-of - A mobile node that is currently configured with a care-of
address SHOULD NOT send Router Solicitations, until its movement address SHOULD NOT send Router Solicitations, until its movement
detection algorithm (Section 10.3) determines that it has moved detection algorithm (Section 10.4) determines that it has moved
and that its current care-of address might no longer be valid. and that its current care-of address might no longer be valid.
7. Requirements for IPv6 Nodes 7. Requirements for IPv6 Nodes
Mobile IPv6 places some special requirements on the functions Mobile IPv6 places some special requirements on the functions
provided by different types of IPv6 nodes. This section summarizes provided by different types of IPv6 nodes. This section summarizes
those requirements, identifying the functionality each requirement those requirements, identifying the functionality each requirement
is intended to support. Further details on this functionality is is intended to support. Further details on this functionality is
provided in the following sections. provided in the following sections.
skipping to change at page 43, line 45 skipping to change at page 45, line 45
7.4. Requirements for IPv6 Mobile Nodes 7.4. Requirements for IPv6 Mobile Nodes
Finally, the following requirements apply to all IPv6 nodes capable Finally, the following requirements apply to all IPv6 nodes capable
of functioning as mobile nodes: of functioning as mobile nodes:
- Every IPv6 mobile node MUST be able to perform IPv6 - Every IPv6 mobile node MUST be able to perform IPv6
decapsulation [4]. decapsulation [4].
- Every IPv6 mobile node MUST support sending Binding Update - Every IPv6 mobile node MUST support sending Binding Update
options, as specified in Sections 10.5, 10.7, and 10.8; and MUST options, as specified in Sections 10.6, 10.8, and 10.9; and MUST
be able to receive and process Binding Acknowledgement options, be able to receive and process Binding Acknowledgement options,
as specified in Section 10.11. as specified in Section 10.12.
- Every IPv6 mobile node MUST support use of the dynamic home agent - Every IPv6 mobile node MUST support use of the dynamic home agent
address discovery mechanism, as described in Section 10.6. address discovery mechanism, as described in Section 10.7.
- Every IPv6 mobile node MUST maintain a Binding Update List in - Every IPv6 mobile node MUST maintain a Binding Update List in
which it records the IP address of each other node to which it which it records the IP address of each other node to which it
has sent a Binding Update, for which the Lifetime sent in that has sent a Binding Update, for which the Lifetime sent in that
binding has not yet expired. binding has not yet expired.
- Every IPv6 mobile node MUST support receiving a Binding Request - Every IPv6 mobile node MUST support receiving a Binding Request
option, by responding with a Binding Update option. option, by responding with a Binding Update option.
- Every IPv6 mobile node MUST support sending packets containing a - Every IPv6 mobile node MUST support sending packets containing a
skipping to change at page 51, line 25 skipping to change at page 53, line 25
If, instead, the sending node has no Binding Cache entry for the If, instead, the sending node has no Binding Cache entry for the
destination address to which the packet is being sent, the sending destination address to which the packet is being sent, the sending
node simply sends the packet normally, with no Routing header. If node simply sends the packet normally, with no Routing header. If
the destination node is not a mobile node (or is a mobile node that the destination node is not a mobile node (or is a mobile node that
is currently at home), the packet will be delivered directly to this is currently at home), the packet will be delivered directly to this
node and processed normally by it. If, however, the destination node node and processed normally by it. If, however, the destination node
is a mobile node that is currently away from home, the packet will is a mobile node that is currently away from home, the packet will
be intercepted by the mobile node's home agent and tunneled (using be intercepted by the mobile node's home agent and tunneled (using
IPv6 encapsulation [4]) to the mobile node's current primary care-of IPv6 encapsulation [4]) to the mobile node's current primary care-of
address, as described in Section 9.6. The mobile node will then send address, as described in Section 9.6. The mobile node will then send
a Binding Update to the sending node, as described in Section 10.7, a Binding Update to the sending node, as described in Section 10.8,
allowing the sending node to create a Binding Cache entry for its use allowing the sending node to create a Binding Cache entry for its use
in sending subsequent packets to this mobile node. in sending subsequent packets to this mobile node.
9. Home Agent Operation 9. Home Agent Operation
9.1. Receiving Router Advertisement Messages 9.1. Receiving Router Advertisement Messages
For each link on which a router provides service as a home agent, the For each link on which a router provides service as a home agent, the
router maintains a Home Agents List recording information about all router maintains a Home Agents List recording information about all
other home agents on that link. This list is used in the dynamic other home agents on that link. This list is used in the dynamic
skipping to change at page 53, line 33 skipping to change at page 55, line 33
expires, after which time the entry MUST be deleted. expires, after which time the entry MUST be deleted.
9.2. Dynamic Home Agent Address Discovery 9.2. Dynamic Home Agent Address Discovery
When a node receives a Binding Update, it MUST validate it and When a node receives a Binding Update, it MUST validate it and
determine the type of Binding Update according to the steps described determine the type of Binding Update according to the steps described
in Section 8.2. This section describes the processing of a valid in Section 8.2. This section describes the processing of a valid
Binding Update that indicates that the mobile node sending it is Binding Update that indicates that the mobile node sending it is
attempting dynamic home agent address discovery. attempting dynamic home agent address discovery.
As described in Section 10.6, a mobile node attempts dynamic home As described in Section 10.7, a mobile node attempts dynamic home
agent address discovery by sending its "home registration" Binding agent address discovery by sending its "home registration" Binding
Update to the "Mobile IPv6 Home-Agents" anycast address [8] for its Update to the "Mobile IPv6 Home-Agents" anycast address [8] for its
home IP subnet prefix (the packet MUST also include a Home Address home IP subnet prefix (the packet MUST also include a Home Address
option). A home agent receiving such a Binding Update that is option). A home agent receiving such a Binding Update that is
serving this subnet (the home agent is configured with this anycast serving this subnet (the home agent is configured with this anycast
address on one of its network interfaces) MUST reject the Binding address on one of its network interfaces) MUST reject the Binding
Update and SHOULD return a Binding Acknowledgement indicating this Update and SHOULD return a Binding Acknowledgement indicating this
rejection, with the Source Address of the packet carrying the Binding rejection, with the Source Address of the packet carrying the Binding
Acknowledgement set to one of the global unicast addresses of the Acknowledgement set to one of the global unicast addresses of the
home agent. The Status field in the Binding Acknowledgement MUST be home agent. The Status field in the Binding Acknowledgement MUST be
skipping to change at page 56, line 22 skipping to change at page 58, line 22
field is set to an appropriate value to indicate the reason for field is set to an appropriate value to indicate the reason for
the rejection. the rejection.
If the home agent does not reject the Binding Update as described If the home agent does not reject the Binding Update as described
above, then it becomes the home agent for the mobile node. The new above, then it becomes the home agent for the mobile node. The new
home agent (the receiving node) MUST then create a new entry in its home agent (the receiving node) MUST then create a new entry in its
Binding Cache for this mobile node (or update its existing Binding Binding Cache for this mobile node (or update its existing Binding
Cache entry for this mobile node, if such an entry already exists) Cache entry for this mobile node, if such an entry already exists)
The home address of the mobile node is taken from the Home Address The home address of the mobile node is taken from the Home Address
field in the packet's Home Address option. The care-of address for field in the packet's Home Address option. The care-of address for
this Binding Cache entry is taken from the Care-of Address field of this Binding Cache entry is taken from the Alternate Care-of Address
the Binding Update (if the Care-of Address Present (C) bit is set in sub-option in the Binding Update option, if present, or from the
the Binding Update) or from the Source Address field in the packet's Source Address field in the packet's IPv6 header, otherwise.
IPv6 header (otherwise).
The home agent MUST mark this Binding Cache entry as a "home The home agent MUST mark this Binding Cache entry as a "home
registration" to indicate that the node is serving as a home registration" to indicate that the node is serving as a home
agent for this binding. Binding Cache entries marked as a "home agent for this binding. Binding Cache entries marked as a "home
registration" MUST be excluded from the normal cache replacement registration" MUST be excluded from the normal cache replacement
policy used for the Binding Cache (Section 8.7) and MUST NOT be policy used for the Binding Cache (Section 8.7) and MUST NOT be
removed from the Binding Cache until the expiration of the Lifetime removed from the Binding Cache until the expiration of the Lifetime
period. period.
In addition, the home agent MUST copy the Router (R) bit from the In addition, the home agent MUST copy the Router (R) bit from the
skipping to change at page 63, line 49 skipping to change at page 65, line 49
options sent previously in an unacknowledged tunneled Router options sent previously in an unacknowledged tunneled Router
Advertisement, the home agent MUST generate a new unique identifer Advertisement, the home agent MUST generate a new unique identifer
for use in the Unique Identifier Sub-Option in the Binding Request for use in the Unique Identifier Sub-Option in the Binding Request
tunneled with the new Router Advertisement. tunneled with the new Router Advertisement.
In addition, as described in Section 9.3, the lifetime returned by a In addition, as described in Section 9.3, the lifetime returned by a
mobile node's home agent in its Binding Acknowledgement in response mobile node's home agent in its Binding Acknowledgement in response
to registration of a new primary care-of address by the mobile node to registration of a new primary care-of address by the mobile node
MUST be no greater than the remaining valid lifetime for the subnet MUST be no greater than the remaining valid lifetime for the subnet
prefix in the mobile node's home address. Furthermore, as described prefix in the mobile node's home address. Furthermore, as described
in Section 10.7, Binding Updates sent by the mobile node to other in Section 10.8, Binding Updates sent by the mobile node to other
nodes MUST use a lifetime no greater than the remaining lifetime of nodes MUST use a lifetime no greater than the remaining lifetime of
its home registration of its primary care-of address. These limits its home registration of its primary care-of address. These limits
on a binding lifetimes ensure that no node uses a mobile node's home on a binding lifetimes ensure that no node uses a mobile node's home
address beyond the time that it becomes invalid. The mobile node address beyond the time that it becomes invalid. The mobile node
SHOULD further limit the lifetimes that it sends on any Binding SHOULD further limit the lifetimes that it sends on any Binding
Updates to be within the remaining preferred lifetime for the prefix Updates to be within the remaining preferred lifetime for the prefix
in its home address. in its home address.
10. Mobile Node Operation 10. Mobile Node Operation
skipping to change at page 65, line 53 skipping to change at page 67, line 53
mobile node's care-of address as the source for such queries will mobile node's care-of address as the source for such queries will
generally have a lower overhead than using the mobile node's generally have a lower overhead than using the mobile node's
home address, since no extra options need be used in either the home address, since no extra options need be used in either the
query or its reply, and all packets can be routed normally, query or its reply, and all packets can be routed normally,
directly between their source and destination without relying directly between their source and destination without relying
on Mobile IP. If the mobile node has no particular knowledge on Mobile IP. If the mobile node has no particular knowledge
that the communication being sent fits within this general type that the communication being sent fits within this general type
of communication, however, the mobile node SHOULD NOT use its of communication, however, the mobile node SHOULD NOT use its
care-of address as the source of the packet in this way. care-of address as the source of the packet in this way.
If the mobile node uses one of its care-of addresses as the source For packets sent by a mobile node while it is at home, no special
of some packet while away from home, no special Mobile IP processing Mobile IP processing is required for sending this packet. Likewise,
is required for sending this packet. The packet is simply addressed if the mobile node uses any address other than its home address as
and transmitted in the same way as any normal IPv6 packet, setting the source of a packet sent while away from home (from the point of
the Source Address field in the packet's IPv6 header to this care-of view of higher protocol layers or applications, as described above),
address. no special Mobile IP processing is required for sending that packet.
In each case, the packet is simply addressed and transmitted in the
same way as any normal IPv6 packet.
On the other hand, if while away from home, the mobile node uses its For each other packet sent by the mobile node (i.e., packets sent
home address as the source of a packet from the point of view of while away from home, using the mobile node's home address as
higher protocol layers or applications as described above, special the source, from the point of view of higher protocol layers and
Mobile IP processing of this packet is required for the insertion of applications), special Mobile IP processing of the packet is required
the Home Address option. Specifically: for the insertion of the Home Address option. Specifically:
- Since Mobile IP is transparent to higher protocol layers (e.g., - Since Mobile IP is transparent to higher protocol layers (e.g.,
to TCP), the packet is initially constructed using the mobile to TCP), the packet is initially constructed using the mobile
node's home address as the packet's Source Address, in the same node's home address as the packet's Source Address, in the same
way as if the mobile node were at home. way as if the mobile node were at home.
- If the mobile node is at home, no special Mobile IP processing - Insert a Home Address option into the packet, with the Home
for this packet is required. The packet is sent normally and the Address field copied from the original value of the Source
following additional steps are not performed.
- Likewise, if the Source Address field in the packet's IPv6 header
is not the mobile node's home address, no special Mobile IP
processing for this packet is required. The packet is sent
normally and the following additional steps are not performed.
- Otherwise, insert a Home Address option into the packet, with the
Home Address field copied from the original value of the Source
Address field in the packet. Address field in the packet.
- Change the Source Address field in the packet's IPv6 header to - Change the Source Address field in the packet's IPv6 header to
one of the mobile node's care-of addresses. This will typically one of the mobile node's care-of addresses. This will typically
be the mobile node's current primary care-of address, but MUST be the mobile node's current primary care-of address, but MUST
be a care-of address with a subnet prefix that is on-link on the be a care-of address with a subnet prefix that is on-link on the
network interface on which the mobile node will transmit the network interface on which the mobile node will transmit the
packet. packet.
This addition of the Home Address option to a packet MUST be By using the care-of address as the Source Address in the IPv6
performed before outgoing IPsec processing, such as the addition of header, with the mobile node's home address instead in the Home
an AH [9] or ESP [10] header to the packet, is performed. Likewise, Address option, the packet will be able to safely pass through any
IPsec processing for a received packet containing a Home Address router implementing ingress filtering [6].
option MUST be performed before the packet is possibly modified as
part of processing the Home Address option. By using the care-of
address as the Source Address in the IPv6 header, with the mobile
node's home address instead in the Home Address option, the packet
will be able to safely pass through any router implementing ingress
filtering [6].
10.2. Receiving Packets While Away from Home 10.2. Interaction with Outbound IPsec Processing
As a guidance to implementors, this section sketches the interaction
between outbound Mobile IP processing and outbound IP Security
(IPsec) processing for packets sent by a mobile node while away
from home. Any specific implementation MAY use algorithms and data
structures other than those suggested here, but its processing
MUST be consistent with these steps and with the relevant IPsec
specifications. In the steps described below, it is assumed that
IPsec is being used in transport mode [11] and that the mobile node
is using its home address as the source for the packet (from the
point of view of higher protocol layers or applications, as described
in Section 10.1):
- The packet is created by higher layer protocols and applications
(e.g., by TCP) as if the mobile node were at home and Mobile IP
were not being used. Mobile IP is transparent to such higher
layers.
- As part of outbound packet processing in IP, the packet is
compared against the IPsec Security Policy Database (SPD) to
determine what processing is required for the packet [11].
- As a special case for Mobile IP, if a Binding Update or
Binding Acknowledgement is being included in the packet, IPsec
authentication and replay protection using AH [9] or ESP [10]
MUST be applied to the packet. If the SPD check above has
already indicated that authentication and replay protection
are required, this processing is sufficient for the Mobile IP
requirement that all packets containing Binding Updates or
Binding Acknowledgements be authenticated and covered by replay
protection. Otherwise, an implementation can force the required
IPsec processing on this individual packet by, for example,
creating a temporary SPD entry for handling of this packet.
- If IPsec processing is required, the packet is either mapped to
an existing Security Association (or SA bundle), or a new SA (or
SA bundle) is created for the packet, according to the procedures
defined for IPsec.
- Since the mobile node is away from home, the mobile node inserts
a Home Address option into the packet, replacing the Source
Address in the packet's IP header with a care-of address suitable
for the link on which the packet is being sent, as described in
Section 10.1. The Home Address option MUST be inserted in a
Destination Options header that appears in the packet after the
AH or ESP header.
- If a Binding Update is being included in the packet, it is also
added to the Destination Options header in the packet.
- Finally, once the packet is fully assembled, the necessary IPsec
authentication (and encryption, if required) processing is
performed on the packet, initializing the Authentication Data in
the AH or ESP header.
10.3. Receiving Packets While Away from Home
While away from home, a mobile node will receive packets addressed to While away from home, a mobile node will receive packets addressed to
its home address, by one of three methods: its home address, by one of three methods:
- Packets sent by a correspondent node that does not have a - Packets sent by a correspondent node that does not have a
Binding Cache entry for the mobile node, will be sent by the Binding Cache entry for the mobile node, will be sent by the
correspondent node in the same way as any normal IP packet. Such correspondent node in the same way as any normal IP packet. Such
packets will then be intercepted by the mobile node's home agent, packets will then be intercepted by the mobile node's home agent,
encapsulated using IPv6 encapsulation [4], and tunneled to the encapsulated using IPv6 encapsulation [4], and tunneled to the
mobile node's primary care-of address. mobile node's primary care-of address.
skipping to change at page 67, line 42 skipping to change at page 70, line 34
moving from this care-of address to another, and if the Binding moving from this care-of address to another, and if the Binding
Cache entry that was created from this Binding Update is still Cache entry that was created from this Binding Update is still
present in this router's Binding Cache, then such a packet present in this router's Binding Cache, then such a packet
will be intercepted by this router, encapsulated using IPv6 will be intercepted by this router, encapsulated using IPv6
encapsulation [4], and tunneled to the mobile node's primary encapsulation [4], and tunneled to the mobile node's primary
care-of address (registered with this router, acting as a home care-of address (registered with this router, acting as a home
agent for this out-of-date care-of address). agent for this out-of-date care-of address).
For packets received by either the first or last of these three For packets received by either the first or last of these three
methods, the mobile node SHOULD send a Binding Update to the original methods, the mobile node SHOULD send a Binding Update to the original
sender of the packet, as described in Section 10.7, subject to the sender of the packet, as described in Section 10.8, subject to the
rate limiting defined in Section 10.10. The mobile node SHOULD rate limiting defined in Section 10.11. The mobile node SHOULD
also process the received packet in the manner defined for IPv6 also process the received packet in the manner defined for IPv6
encapsulation [4], which will result in the encapsulated (inner) encapsulation [4], which will result in the encapsulated (inner)
packet being processed normally by upper-layer protocols within the packet being processed normally by upper-layer protocols within the
mobile node, as if it had been addressed (only) to the mobile node's mobile node, as if it had been addressed (only) to the mobile node's
home address. home address.
For packets received by the second method above (using a Routing For packets received by the second method above (using a Routing
header), the mobile node SHOULD process the received packet in the header), the mobile node SHOULD process the received packet in the
manner defined for the type of IPv6 Routing header used [5], which manner defined for the type of IPv6 Routing header used [5], which
will result in the packet being processed normally by upper-layer will result in the packet being processed normally by upper-layer
skipping to change at page 68, line 20 skipping to change at page 71, line 12
packets sent by upper-layer protocols, if the received packet is packets sent by upper-layer protocols, if the received packet is
authenticated [5]. If this is done for upper-layer protocol response authenticated [5]. If this is done for upper-layer protocol response
packets sent by a mobile node while away from home, the mobile packets sent by a mobile node while away from home, the mobile
node SHOULD NOT include its own care-of address, which appears in node SHOULD NOT include its own care-of address, which appears in
the Routing header of the received packet, in the reversed route the Routing header of the received packet, in the reversed route
for the response packet. If the received Routing header contained for the response packet. If the received Routing header contained
no additional hops (other than the mobile node's home address and no additional hops (other than the mobile node's home address and
care-of address), then any upper-layer protocol response packet care-of address), then any upper-layer protocol response packet
SHOULD NOT include a Routing header. SHOULD NOT include a Routing header.
10.3. Movement Detection 10.4. Movement Detection
A mobile node MAY use any combination of mechanisms available to it A mobile node MAY use any combination of mechanisms available to it
to detect when it has moved from one link to another. The primary to detect when it has moved from one link to another. The primary
movement detection mechanism for Mobile IPv6 defined here uses the movement detection mechanism for Mobile IPv6 defined here uses the
facilities of IPv6 Neighbor Discovery, including Router Discovery and facilities of IPv6 Neighbor Discovery, including Router Discovery and
Neighbor Unreachability Detection. The description here is based on Neighbor Unreachability Detection. The description here is based on
the conceptual model of the organization and data structures defined the conceptual model of the organization and data structures defined
by Neighbor Discovery [14]. by Neighbor Discovery [14].
Mobile nodes SHOULD use Router Discovery to discover new routers and Mobile nodes SHOULD use Router Discovery to discover new routers and
skipping to change at page 68, line 49 skipping to change at page 71, line 41
from the Router Advertisement) used to expire the entry when it from the Router Advertisement) used to expire the entry when it
becomes invalid. becomes invalid.
While away from home, a mobile node SHOULD select one router from While away from home, a mobile node SHOULD select one router from
its Default Router List to use as its default router, and one subnet its Default Router List to use as its default router, and one subnet
prefix advertised by that router from its Prefix List to use as prefix advertised by that router from its Prefix List to use as
the subnet prefix in its primary care-of address. A mobile node the subnet prefix in its primary care-of address. A mobile node
MAY also have associated additional care-of addresses, using other MAY also have associated additional care-of addresses, using other
subnet prefixes from its Prefix List. The method by which a mobile subnet prefixes from its Prefix List. The method by which a mobile
node selects and forms a care-of address from the available subnet node selects and forms a care-of address from the available subnet
prefixes is described in Section 10.4. The mobile node registers prefixes is described in Section 10.5. The mobile node registers
its primary care-of address with its home agent, as described in its primary care-of address with its home agent, as described in
Section 10.5. Section 10.6.
While a mobile node is away from home and using some router as its While a mobile node is away from home and using some router as its
default router, it is important for the mobile node to be able to default router, it is important for the mobile node to be able to
quickly detect when that router becomes unreachable, so that it can quickly detect when that router becomes unreachable, so that it can
switch to a new default router and to a new primary care-of address. switch to a new default router and to a new primary care-of address.
Since some links (notably wireless) do not necessarily work equally Since some links (notably wireless) do not necessarily work equally
well in both directions, it is likewise important for the mobile well in both directions, it is likewise important for the mobile
node to detect when it becomes unreachable to packets sent from its node to detect when it becomes unreachable to packets sent from its
default router, so that the mobile node can take steps to ensure that default router, so that the mobile node can take steps to ensure that
any correspondent nodes attempting to communicate with it can still any correspondent nodes attempting to communicate with it can still
skipping to change at page 71, line 16 skipping to change at page 74, line 7
node is reachable. For example, a mobile node MAY use signal node is reachable. For example, a mobile node MAY use signal
strength or signal quality information (with suitable hysteresis) for strength or signal quality information (with suitable hysteresis) for
its link with the available routers to decide when to switch to a new its link with the available routers to decide when to switch to a new
primary care-of address using that router rather than its current primary care-of address using that router rather than its current
default router (and current primary care-of address). Even though default router (and current primary care-of address). Even though
the mobile node's current default router may still be reachable in the mobile node's current default router may still be reachable in
terms of Neighbor Unreachability Detection, the mobile node MAY use terms of Neighbor Unreachability Detection, the mobile node MAY use
such lower-layer information to determine that switching to a new such lower-layer information to determine that switching to a new
default router would provide a better connection. default router would provide a better connection.
10.4. Forming New Care-of Addresses 10.5. Forming New Care-of Addresses
After detecting that it has moved from one link to another (i.e., its After detecting that it has moved from one link to another (i.e., its
current default router has become unreachable and it has discovered current default router has become unreachable and it has discovered
a new default router), a mobile node SHOULD form a new primary a new default router), a mobile node SHOULD form a new primary
care-of address using one of the on-link subnet prefixes advertised care-of address using one of the on-link subnet prefixes advertised
by the new router. A mobile node MAY form a new primary care-of by the new router. A mobile node MAY form a new primary care-of
address at any time, except that it MUST NOT do so too frequently. address at any time, except that it MUST NOT do so too frequently.
Specifically, a mobile node MUST NOT send a Binding Update about a Specifically, a mobile node MUST NOT send a Binding Update about a
new care-of address to its home agent (which is required to register new care-of address to its home agent (which is required to register
the new address as its primary care-of address) more often than once the new address as its primary care-of address) more often than once
skipping to change at page 71, line 40 skipping to change at page 74, line 31
node MAY form a new (non-primary) care-of address using that subnet node MAY form a new (non-primary) care-of address using that subnet
prefix, even when it has not switched to a new default router. A prefix, even when it has not switched to a new default router. A
mobile node can have only one primary care-of address at a time mobile node can have only one primary care-of address at a time
(which is registered with its home agent), but it MAY have an (which is registered with its home agent), but it MAY have an
additional care-of address for any or all of the prefixes on its additional care-of address for any or all of the prefixes on its
current link. Furthermore, since a wireless network interface may current link. Furthermore, since a wireless network interface may
actually allow a mobile node to be reachable on more than one link at actually allow a mobile node to be reachable on more than one link at
a time (i.e., within wireless transmitter range of routers on more a time (i.e., within wireless transmitter range of routers on more
than one separate link), a mobile node MAY have care-of addresses than one separate link), a mobile node MAY have care-of addresses
on more than one link at a time. The use of more than one care-of on more than one link at a time. The use of more than one care-of
address at a time is described in Section 10.15. address at a time is described in Section 10.16.
As described in Section 4, in order to form a new care-of address, As described in Section 4, in order to form a new care-of address,
a mobile node MAY use either stateless [23] or stateful (e.g., a mobile node MAY use either stateless [23] or stateful (e.g.,
DHCPv6 [2]) Address Autoconfiguration. If a mobile node needs to DHCPv6 [2]) Address Autoconfiguration. If a mobile node needs to
send packets as part of the method of address autoconfiguration, send packets as part of the method of address autoconfiguration,
it MUST use an IPv6 link-local address rather than its own IPv6 it MUST use an IPv6 link-local address rather than its own IPv6
home address as the Source Address in the IPv6 header of each such home address as the Source Address in the IPv6 header of each such
autoconfiguration packet. autoconfiguration packet.
In some cases, a mobile node may already know a (constant) IPv6 In some cases, a mobile node may already know a (constant) IPv6
address that has been assigned to it for its use only while address that has been assigned to it for its use only while
visiting a specific foreign link. For example, a mobile node may be visiting a specific foreign link. For example, a mobile node may be
statically configured with an IPv6 address assigned by the system statically configured with an IPv6 address assigned by the system
administrator of some foreign link, for its use while visiting that administrator of some foreign link, for its use while visiting that
link. If so, rather than using Address Autoconfiguration to form a link. If so, rather than using Address Autoconfiguration to form a
new care-of address using this subnet prefix, the mobile node MAY use new care-of address using this subnet prefix, the mobile node MAY use
its own pre-assigned address as its care-of address on this link. its own pre-assigned address as its care-of address on this link.
10.5. Sending Binding Updates to the Home Agent 10.6. Sending Binding Updates to the Home Agent
After deciding to change its primary care-of address as described After deciding to change its primary care-of address as described
in Sections 10.3 and 10.4, a mobile node MUST register this care-of in Sections 10.4 and 10.5, a mobile node MUST register this care-of
address with its home agent in order to make this its primary care-of address with its home agent in order to make this its primary care-of
address. To do so, the mobile node sends a packet to its home agent address. To do so, the mobile node sends a packet to its home agent
containing a Binding Update option, with the packet constructed as containing a Binding Update option, with the packet constructed as
follows: follows:
- The Home Registration (H) bit MUST be set in the Binding Update. - The Home Registration (H) bit MUST be set in the Binding Update.
- The Acknowledge (A) bit MUST be set in the Binding Update. - The Acknowledge (A) bit MUST be set in the Binding Update.
- The packet MUST contain a Home Address option, giving the mobile - The packet MUST contain a Home Address option, giving the mobile
node's home address for the binding. node's home address for the binding.
- The care-of address for the binding MUST be used as the Source - The care-of address for the binding MUST be used as the Source
Address in the packet's IPv6 header, or the Care-of Address Address in the packet's IPv6 header, unless an Alternate Care-of
Present (C) bit MUST be set in the Binding Update and the care-of Address sub-option is included in the Binding Update option.
address for the binding MUST be specified in the Care-of Address
field in the Binding Update.
- The Prefix Length field SHOULD be set to the length of the mobile - The Prefix Length field SHOULD be set to the length of the mobile
node's subnet prefix in its home address, to request the mobile node's subnet prefix in its home address, to request the mobile
node's home agent to serve as a home agent for all home addresses node's home agent to serve as a home agent for all home addresses
for the mobile node based on all on-link subnet prefixes on the for the mobile node based on all on-link subnet prefixes on the
home link. Otherwise, this field MUST be set to zero. home link. Otherwise, this field MUST be set to zero.
The Acknowledge (A) bit in the Binding Update requests the home The Acknowledge (A) bit in the Binding Update requests the home
agent to return a Binding Acknowledgement in response to this agent to return a Binding Acknowledgement in response to this
Binding Update. As described in Section 5.2, the mobile node SHOULD Binding Update. As described in Section 5.2, the mobile node SHOULD
skipping to change at page 73, line 20 skipping to change at page 76, line 10
If the mobile node has additional home addresses using a different If the mobile node has additional home addresses using a different
interface identifier, then the mobile node SHOULD send an additional interface identifier, then the mobile node SHOULD send an additional
packet containing a Binding Update to its home agent to register packet containing a Binding Update to its home agent to register
the care-of address for each such other home address (or set of the care-of address for each such other home address (or set of
home addresses sharing an interface identifier). These additional home addresses sharing an interface identifier). These additional
Binding Updates MUST each be sent as a separate packet, since each Binding Updates MUST each be sent as a separate packet, since each
MUST contain an AH [9] or ESP [10] header to authenticate the Binding MUST contain an AH [9] or ESP [10] header to authenticate the Binding
Update as coming from the home address being bound. Update as coming from the home address being bound.
10.6. Dynamic Home Agent Address Discovery 10.7. Dynamic Home Agent Address Discovery
It is possible that when the mobile node needs to send a Binding It is possible that when the mobile node needs to send a Binding
Update to its home agent to register its new primary care-of address, Update to its home agent to register its new primary care-of address,
as described in Section 10.5, the mobile node may not know the as described in Section 10.6, the mobile node may not know the
address of any router on its home link that can serve as a home agent address of any router on its home link that can serve as a home agent
for it. For example, some nodes on its home link may have been for it. For example, some nodes on its home link may have been
reconfigured while the mobile node has been away from home, such that reconfigured while the mobile node has been away from home, such that
the router that was operating as the mobile node's home agent has the router that was operating as the mobile node's home agent has
been replaced by a different router serving this role. been replaced by a different router serving this role.
In this case, the mobile node SHOULD use the dynamic home agent In this case, the mobile node SHOULD use the dynamic home agent
address discovery procedure to find the address of a suitable home address discovery procedure to find the address of a suitable home
agent on its home link. To do so, the mobile node sends the packet, agent on its home link. To do so, the mobile node sends the packet,
as described above, with the Destination Address in the packet's as described above, with the Destination Address in the packet's
skipping to change at page 74, line 4 skipping to change at page 76, line 44
agents in turn, by sending each a Binding Update and waiting for the agents in turn, by sending each a Binding Update and waiting for the
matching Binding Acknowledgement, until its registration is accepted matching Binding Acknowledgement, until its registration is accepted
by one of these home agents. by one of these home agents.
If the mobile node has a current registration with some home agent If the mobile node has a current registration with some home agent
on its home link (the Lifetime for that registration has not yet on its home link (the Lifetime for that registration has not yet
expired), then the mobile node MUST attempt any new registration expired), then the mobile node MUST attempt any new registration
first with that home agent. If that registration attempt fails first with that home agent. If that registration attempt fails
(e.g., times out or is rejected), the mobile node SHOULD then (e.g., times out or is rejected), the mobile node SHOULD then
reattempt this registration with another home agent on its home link. reattempt this registration with another home agent on its home link.
If the mobile node knows of no other suitable home agent, then it MAY If the mobile node knows of no other suitable home agent, then it MAY
attempt the dynamic home agent address discovery procedure described attempt the dynamic home agent address discovery procedure described
above. above.
10.7. Sending Binding Updates to Correspondent Nodes 10.8. Sending Binding Updates to Correspondent Nodes
A mobile node MAY send a Binding Update to any correspondent node at A mobile node MAY send a Binding Update to any correspondent node at
any time to allow the correspondent node to cache the mobile node's any time to allow the correspondent node to cache the mobile node's
current care-of address (subject to the rate limiting defined in current care-of address (subject to the rate limiting defined in
Section 10.10). In any Binding Update sent by a mobile node, the Section 10.11). In any Binding Update sent by a mobile node, the
care-of address (either the Source Address in the packet's IPv6 care-of address (either the Source Address in the packet's IPv6
header or the Care-of Address field in the Binding Update) MUST be header or the Care-of Address field in the Binding Update) MUST be
set to one of the care-of addresses currently in use by the mobile set to one of the care-of addresses currently in use by the mobile
node or to the mobile node's home address. node or to the mobile node's home address.
If set to one of the mobile node's current care-of addresses (the If set to one of the mobile node's current care-of addresses (the
care-of address given MAY differ from the mobile node's primary care-of address given MAY differ from the mobile node's primary
care-of address), the Binding Update requests the correspondent node care-of address), the Binding Update requests the correspondent node
to create or update an entry for the mobile node in the correspondent to create or update an entry for the mobile node in the correspondent
node's Binding Cache to record this care-of address for use in node's Binding Cache to record this care-of address for use in
skipping to change at page 75, line 9 skipping to change at page 77, line 49
The mobile node MUST retain in its Binding Update List information The mobile node MUST retain in its Binding Update List information
about all Binding Updates sent, for which the lifetime of the binding about all Binding Updates sent, for which the lifetime of the binding
has not yet expired. However, when sending a Binding Update, if an has not yet expired. However, when sending a Binding Update, if an
entry already exists in the mobile node's Binding Update List for entry already exists in the mobile node's Binding Update List for
an earlier Binding Update sent to that same destination node, the an earlier Binding Update sent to that same destination node, the
existing Binding Update List entry is updated to reflect the new existing Binding Update List entry is updated to reflect the new
Binding Update rather than creating a new Binding Update List entry. Binding Update rather than creating a new Binding Update List entry.
In general, when a mobile node sends a Binding Update to its home In general, when a mobile node sends a Binding Update to its home
agent to register a new primary care-of address (as described in agent to register a new primary care-of address (as described in
Section 10.5), the mobile node will also send a Binding Update to Section 10.6), the mobile node will also send a Binding Update to
each other node for which an entry exists in the mobile node's each other node for which an entry exists in the mobile node's
Binding Update List. Thus, other relevant nodes are generally kept Binding Update List. Thus, other relevant nodes are generally kept
updated about the mobile node's binding and can send packets directly updated about the mobile node's binding and can send packets directly
to the mobile node using the mobile node's current care-of address. to the mobile node using the mobile node's current care-of address.
The mobile node, however, need not send these Binding Updates The mobile node, however, need not send these Binding Updates
immediately after configuring a new care-of address. For example, immediately after configuring a new care-of address. For example,
since the Binding Update is a destination option and can be included since the Binding Update is a destination option and can be included
in any packet sent by a mobile node, the mobile node MAY delay in any packet sent by a mobile node, the mobile node MAY delay
sending a new Binding Update to any correspondent node for a sending a new Binding Update to any correspondent node for a
skipping to change at page 75, line 36 skipping to change at page 78, line 26
correspondent node is needed, and SHOULD include the new Binding correspondent node is needed, and SHOULD include the new Binding
Update in this packet as necessary. Update in this packet as necessary.
In addition, when a mobile node receives a packet for which the In addition, when a mobile node receives a packet for which the
mobile node can deduce that the original sender of the packet has mobile node can deduce that the original sender of the packet has
no Binding Cache entry for the mobile node, or for which the mobile no Binding Cache entry for the mobile node, or for which the mobile
node can deduce that the original sender of the packet has an node can deduce that the original sender of the packet has an
out-of-date care-of address for the mobile node in its Binding Cache, out-of-date care-of address for the mobile node in its Binding Cache,
the mobile node SHOULD return a Binding Update to the sender giving the mobile node SHOULD return a Binding Update to the sender giving
its current care-of address (subject to the rate limiting defined its current care-of address (subject to the rate limiting defined
in Section 10.10). In particular, the mobile node SHOULD return a in Section 10.11). In particular, the mobile node SHOULD return a
Binding Update in response to receiving a packet that meets all of Binding Update in response to receiving a packet that meets all of
the following tests: the following tests:
- The packet was tunneled using IPv6 encapsulation. - The packet was tunneled using IPv6 encapsulation.
- The Destination Address in the tunnel (outer) IPv6 header is - The Destination Address in the tunnel (outer) IPv6 header is
equal to any of the mobile node's care-of addresses. equal to any of the mobile node's care-of addresses.
- The Destination Address in the original (inner) IPv6 header - The Destination Address in the original (inner) IPv6 header
is equal to one of the mobile node's home addresses; or this is equal to one of the mobile node's home addresses; or this
Destination Address is equal to one of the mobile node's previous Destination Address is equal to one of the mobile node's previous
care-of addresses, if the mobile node has an entry in its Binding care-of addresses, if the mobile node has an entry in its Binding
Update List representing an unexpired Binding Update sent to Update List representing an unexpired Binding Update sent to
a previous default router for this previous care-of address a previous default router for this previous care-of address
(Section 10.8). (Section 10.9).
- The Source Address in the tunnel (outer) IPv6 header differs from - The Source Address in the tunnel (outer) IPv6 header differs from
the Source Address in the original (inner) IPv6 header. the Source Address in the original (inner) IPv6 header.
The destination address to which the Binding Update should be sent The destination address to which the Binding Update should be sent
in response to receiving a packet meeting all of the above tests is in response to receiving a packet meeting all of the above tests is
the Source Address in the original (inner) IPv6 header of the packet. the Source Address in the original (inner) IPv6 header of the packet.
The home address for which this Binding Update is sent should be the The home address for which this Binding Update is sent should be the
Destination Address of the original (inner) packet. Destination Address of the original (inner) packet.
skipping to change at page 76, line 31 skipping to change at page 79, line 18
period has reached MAX_BINDACK_TIMEOUT. period has reached MAX_BINDACK_TIMEOUT.
A mobile node MAY choose to keep its location private from certain A mobile node MAY choose to keep its location private from certain
correspondent nodes, and thus need not send new Binding Updates to correspondent nodes, and thus need not send new Binding Updates to
those correspondents. A mobile node MAY also send a Binding Update those correspondents. A mobile node MAY also send a Binding Update
to such a correspondent node to instruct it to delete any existing to such a correspondent node to instruct it to delete any existing
binding for the mobile node from its Binding Cache, as described in binding for the mobile node from its Binding Cache, as described in
Section 5.1. No other IPv6 nodes are authorized to send Binding Section 5.1. No other IPv6 nodes are authorized to send Binding
Updates on behalf of a mobile node. Updates on behalf of a mobile node.
10.8. Sending Binding Updates to the Previous Default Router 10.9. Establishing Forwarding from a Previous Care-of Address
After switching to a new default router (and thus also changing its When a mobile node connects to a new link and forms a new care-of
primary care-of address), a mobile node MAY send a Binding Update to address, it MAY establish forwarding of packets from a previous
its previous default router, giving its new care-of address. The care-of address to this new care-of address. To do so, the mobile
packet carrying the Binding Update MUST be addressed to the mobile node sends a Binding Update to any home agent on the link on which
node's previous default router's global unicast address, learned the previous care-of address is located, indicating this previous
by the mobile node based on Prefix Information options received in care-of address as the home address for the binding, and giving its
Router Advertisements from it in which the Router Address (R) bit is new care-of address as the binding's care-of address. Such packet
set (Sections 4.3 and 6.2). forwarding allows packets destined to the mobile node from nodes that
have not yet learned the mobile node's new care-of address, to be
forwarded to the mobile node rather than being lost once the mobile
node is no longer reachable at this previous care-of address.
If the mobile node sends such a Binding Update, the home address In constructing this Binding Update, the mobile node utilizes the
for the binding, specified in the Home Address option included in following specific steps:
the packet carrying this Binding Update, MUST be set the mobile
node's old primary care-of address (that it used while using this - The Home Address field in the Home Address option in the packet
default router), and the care-of address for the binding (either the carrying the Binding Update MUST be set to the previous care-of
Source Address in the packet's IPv6 header or the Care-of Address address for which packet forwarding is being established.
field in the Binding Update) MUST be set to the mobile node's new
primary care-of address. In addition, the Home Registration (H) - The care-of address for the new binding MUST be set to the new
bit MUST also be set in this Binding Update, to request the mobile care-of address to which packets destined to the previous care-of
node's previous default router to temporarily act as a home agent address are to be forwarded. Normally, this care-of address for
for the mobile node's old primary care-of address. The previous the binding is specified by setting the Source Address of the
default router will thus tunnel packets for the mobile node to its packet carrying the Binding Update, to this address. However,
new care-of address. All of the procedures defined for home agent the mobile node MAY instead include an Alternate Care-of Address
operation must be followed by this previous default router for this sub-option in the Binding Update option, with its Alternate
registration. Note that the previous router does not necessarily Care-of Address field set to the care-of address for the binding.
know the mobile node's (permanent) home address as part of this
- The Home Registration (H) bit MUST also be set in this Binding
Update, to request this home agent to temporarily act as a home
agent for this previous care-of address.
This home agent will thus tunnel packets for the mobile node (packets
destined to its specified previous care-of address) to its new
care-of address. All of the procedures defined for home agent
operation MUST be followed by this home agent for this registration.
Note that this home agent does not necessarily know (and need not
know) the mobile node's (permanent) home address as part of this
registration. registration.
10.9. Retransmitting Binding Updates The packet carrying the Binding Update MUST be addressed to
this home agent's global unicast address. Normally, this global
unicast address is learned by the mobile node based on the Router
Advertisements received by the mobile node (Section 6.2) while
attached to the link on which this previous care-of address and this
home agent are located; the mobile node obtains this home agent
address from its Home Agents List (Section 4.3) before clearing the
list upon connecting to the new link. Alternatively, the mobile
node MAY use dynamic home agent address discovery (Section 10.7) to
discover the global unicast address of a home agent on this previous
link, but it SHOULD use the address from its Home Agents List if
available.
10.10. Retransmitting Binding Updates
If, after sending a Binding Update in which the Acknowledge (A) bit If, after sending a Binding Update in which the Acknowledge (A) bit
is set, a mobile node fails to receive a Binding Acknowledgement is set, a mobile node fails to receive a Binding Acknowledgement
within INITIAL_BINDACK_TIMEOUT seconds, the mobile node SHOULD within INITIAL_BINDACK_TIMEOUT seconds, the mobile node SHOULD
retransmit the Binding Update until a Binding Acknowledgement retransmit the Binding Update until a Binding Acknowledgement
is received. Such a retransmitted Binding Update MUST use the is received. Such a retransmitted Binding Update MUST use the
same Sequence Number value as the original transmission. The same Sequence Number value as the original transmission. The
retransmissions by the mobile node MUST use an exponential retransmissions by the mobile node MUST use an exponential
back-off process, in which the timeout period is doubled back-off process, in which the timeout period is doubled
upon each retransmission until either the node receives a upon each retransmission until either the node receives a
Binding Acknowledgement or the timeout period reaches the value Binding Acknowledgement or the timeout period reaches the value
MAX_BINDACK_TIMEOUT. MAX_BINDACK_TIMEOUT.
10.10. Rate Limiting for Sending Binding Updates 10.11. Rate Limiting for Sending Binding Updates
A mobile node MUST NOT send Binding Updates about the same binding A mobile node MUST NOT send Binding Updates about the same binding
to any node more often than once per MAX_UPDATE_RATE seconds. After to any node more often than once per MAX_UPDATE_RATE seconds. After
sending MAX_FAST_UPDATES consecutive Binding Updates to a particular sending MAX_FAST_UPDATES consecutive Binding Updates to a particular
node with the same care-of address, the mobile node SHOULD reduce node with the same care-of address, the mobile node SHOULD reduce
its rate of sending Binding Updates to that node, to the rate of its rate of sending Binding Updates to that node, to the rate of
SLOW_UPDATE_RATE per second. The mobile node MAY continue to send SLOW_UPDATE_RATE per second. The mobile node MAY continue to send
Binding Updates at this slower rate indefinitely, in hopes that the Binding Updates at this slower rate indefinitely, in hopes that the
node will eventually be able to process a Binding Update and begin node will eventually be able to process a Binding Update and begin
to route its packets directly to the mobile node at its new care-of to route its packets directly to the mobile node at its new care-of
address. address.
10.11. Receiving Binding Acknowledgements 10.12. Receiving Binding Acknowledgements
Upon receiving a packet carrying a Binding Acknowledgement, a mobile Upon receiving a packet carrying a Binding Acknowledgement, a mobile
node MUST validate the packet according to the following tests: node MUST validate the packet according to the following tests:
- The packet contains a valid AH [9] or ESP [10] header providing - The packet contains a valid AH [9] or ESP [10] header providing
sender authentication, data integrity protection, and replay sender authentication, data integrity protection, and replay
protection. protection.
- The Option Length field in the option is greater than or equal to - The Option Length field in the option is greater than or equal to
11 octets. 11 octets.
skipping to change at page 78, line 31 skipping to change at page 81, line 43
List to indicate that the Binding Update has been acknowledged. List to indicate that the Binding Update has been acknowledged.
The mobile node MUST then stop retransmitting the Binding Update. The mobile node MUST then stop retransmitting the Binding Update.
- If the Status field indicates that the Binding Update was - If the Status field indicates that the Binding Update was
rejected (the Status field is greater than or equal to 128), then rejected (the Status field is greater than or equal to 128), then
the mobile node MUST delete the corresponding Binding Update List the mobile node MUST delete the corresponding Binding Update List
entry (and MUST also stop retransmitting the Binding Update). entry (and MUST also stop retransmitting the Binding Update).
Optionally, the mobile node MAY then take steps to correct the Optionally, the mobile node MAY then take steps to correct the
cause of the error and retransmit the Binding Update (with a new cause of the error and retransmit the Binding Update (with a new
Sequence Number value), subject to the rate limiting restriction Sequence Number value), subject to the rate limiting restriction
specified in Section 10.10. In particular, if the Status field specified in Section 10.11. In particular, if the Status field
is equal to 135 (dynamic home agent address discovery response), is equal to 135 (dynamic home agent address discovery response),
then the mobile node MAY reattempt its home registration with then the mobile node MAY reattempt its home registration with
the home agent address given in the Source Address field of the the home agent address given in the Source Address field of the
packet carrying the Binding Acknowledgement or with any of the packet carrying the Binding Acknowledgement or with any of the
home agent IP addresses listed in the Home Agents List Sub-Option home agent IP addresses listed in the Home Agents List Sub-Option
in the Binding Acknowledgement. If any of these addresses is not in the Binding Acknowledgement. If any of these addresses is not
a global unicast address or does not have a subnet prefix equal a global unicast address or does not have a subnet prefix equal
to the mobile node's own subnet prefix, then that particular to the mobile node's own subnet prefix, then that particular
address MUST be ignored and the mobile node MUST NOT reattempt address MUST be ignored and the mobile node MUST NOT reattempt
its home registration with that home agent. its home registration with that home agent.
10.12. Receiving Binding Requests 10.13. Receiving Binding Requests
When a mobile node receives a packet containing a Binding Request, When a mobile node receives a packet containing a Binding Request,
it SHOULD return to the sender a packet containing a Binding Update. it SHOULD return to the sender a packet containing a Binding Update.
The Lifetime field in this Binding Update SHOULD be set to a new The Lifetime field in this Binding Update SHOULD be set to a new
lifetime, extending any current lifetime remaining from a previous lifetime, extending any current lifetime remaining from a previous
Binding Update sent to this node (as indicated in any existing Binding Update sent to this node (as indicated in any existing
Binding Update List entry for this node), except that this lifetime Binding Update List entry for this node), except that this lifetime
MUST NOT exceed the remaining lifetime for the mobile node's primary MUST NOT exceed the remaining lifetime for the mobile node's primary
care-of address registration at its home agent. When sending this care-of address registration at its home agent. When sending this
Binding Update, the mobile node MUST update its Binding Update List Binding Update, the mobile node MUST update its Binding Update List
skipping to change at page 79, line 19 skipping to change at page 82, line 31
case, the mobile node instead SHOULD returns a Binding Update to the case, the mobile node instead SHOULD returns a Binding Update to the
sender, in which the Lifetime field is set to zero and the care-of sender, in which the Lifetime field is set to zero and the care-of
address is set to the mobile node's home address. address is set to the mobile node's home address.
If the Binding Request for which the Binding Update is being returned If the Binding Request for which the Binding Update is being returned
contains a Unique Identifer Sub-Option, the Binding Update MUST also contains a Unique Identifer Sub-Option, the Binding Update MUST also
include a Unique Identifier Sub-Option. The unique identifier in the include a Unique Identifier Sub-Option. The unique identifier in the
SUb-Option Data field of the Unique Identifier Sub-Option MUST be SUb-Option Data field of the Unique Identifier Sub-Option MUST be
copied from the unique identifier carried in the Binding Request. copied from the unique identifier carried in the Binding Request.
10.13. Receiving ICMP Error Messages 10.14. Receiving ICMP Error Messages
The Option Type value for a Binding Update option specifies that The Option Type value for a Binding Update option specifies that
any node receiving this option that does not recognize the Option any node receiving this option that does not recognize the Option
Type SHOULD return an ICMP Parameter Problem, Code 2, message to Type SHOULD return an ICMP Parameter Problem, Code 2, message to
the sender of the packet containing the Binding Update option. If the sender of the packet containing the Binding Update option. If
a node sending a Binding Update receives such an ICMP error message a node sending a Binding Update receives such an ICMP error message
in response, it should record in its Binding Update List that future in response, it should record in its Binding Update List that future
Binding Updates should not be sent to this destination. Binding Updates should not be sent to this destination.
Likewise, although ALL IPv6 nodes (whether host or router, whether Likewise, although ALL IPv6 nodes (whether host or router, whether
skipping to change at page 79, line 46 skipping to change at page 83, line 8
this option that does not recognize the Option Type SHOULD return this option that does not recognize the Option Type SHOULD return
an ICMP Parameter Problem, Code 2, message to the sender of the an ICMP Parameter Problem, Code 2, message to the sender of the
packet containing the Home Address option. If a mobile node receives packet containing the Home Address option. If a mobile node receives
such an ICMP error message from some node indicating that it does such an ICMP error message from some node indicating that it does
not recognize the mobile node's Home Address option, the mobile not recognize the mobile node's Home Address option, the mobile
node SHOULD log the error and then discard the ICMP message; this node SHOULD log the error and then discard the ICMP message; this
error message indicates that the node to which the original packet error message indicates that the node to which the original packet
was addressed (the node returning the ICMP error message) does not was addressed (the node returning the ICMP error message) does not
correctly implement this required part of the IPv6 protocol. correctly implement this required part of the IPv6 protocol.
10.14. Receiving Tunneled Router Advertisements 10.15. Receiving Tunneled Router Advertisements
Section 9.7 describes the operation of a home agent to support Section 9.7 describes the operation of a home agent to support
renumbering a mobile node's home subnet while the mobile node is renumbering a mobile node's home subnet while the mobile node is
away from home. The home agent tunnels certain Router Advertisement away from home. The home agent tunnels certain Router Advertisement
messages to the mobile node while away from home, giving "important" messages to the mobile node while away from home, giving "important"
Prefix Information options that describe changes in the prefixes in Prefix Information options that describe changes in the prefixes in
use on the mobile node's home link. use on the mobile node's home link.
When a mobile node receives a tunneled Router Advertisement, it MUST When a mobile node receives a tunneled Router Advertisement, it MUST
validate it according to the following tests: validate it according to the following tests:
skipping to change at page 80, line 44 skipping to change at page 84, line 5
In addition, in processing the packet containing this Router In addition, in processing the packet containing this Router
Advertisement, the mobile node SHOULD return to the home agent a Advertisement, the mobile node SHOULD return to the home agent a
Binding Update in response to the Binding Request carried in the Binding Update in response to the Binding Request carried in the
packet. The correct formation of this Binding Update by the mobile packet. The correct formation of this Binding Update by the mobile
node and processing of it by the home agent will be viewed by the node and processing of it by the home agent will be viewed by the
home agent as an acknowledgement of this Router Advertisement, home agent as an acknowledgement of this Router Advertisement,
confirming to it that this Router Advertisement was received by the confirming to it that this Router Advertisement was received by the
mobile node. mobile node.
10.15. Using Multiple Care-of Addresses 10.16. Using Multiple Care-of Addresses
As described in Section 10.4, a mobile node MAY use more than one As described in Section 10.5, a mobile node MAY use more than one
care-of address at a time. Particularly in the case of many wireless care-of address at a time. Particularly in the case of many wireless
networks, a mobile node effectively might be reachable through networks, a mobile node effectively might be reachable through
multiple links at the same time (e.g., with overlapping wireless multiple links at the same time (e.g., with overlapping wireless
cells), on which different on-link subnet prefixes may exist. A cells), on which different on-link subnet prefixes may exist. A
mobile node SHOULD select a primary care-of address from among those mobile node SHOULD select a primary care-of address from among those
care-of addresses it has formed using any of these subnet prefixes, care-of addresses it has formed using any of these subnet prefixes,
based on the movement detection mechanism in use, as described in based on the movement detection mechanism in use, as described in
Section 10.3. When the mobile node selects a new primary care-of Section 10.4. When the mobile node selects a new primary care-of
address, it MUST register it with its home agent by sending it a address, it MUST register it with its home agent by sending it a
Binding Update with the Home Registration (H) and Acknowledge (A) Binding Update with the Home Registration (H) and Acknowledge (A)
bits set, as described in Section 10.5. bits set, as described in Section 10.6.
To assist with smooth handoffs, a mobile node SHOULD retain To assist with smooth handoffs, a mobile node SHOULD retain
its previous primary care-of address as a (non-primary) care-of its previous primary care-of address as a (non-primary) care-of
address, and SHOULD still accept packets at this address, even after address, and SHOULD still accept packets at this address, even after
registering its new primary care-of address with its home agent. registering its new primary care-of address with its home agent.
This is reasonable, since the mobile node could only receive packets This is reasonable, since the mobile node could only receive packets
at its previous primary care-of address if it were indeed still at its previous primary care-of address if it were indeed still
connected to that link. If the previous primary care-of address was connected to that link. If the previous primary care-of address was
allocated using stateful Address Autoconfiguration [2], the mobile allocated using stateful Address Autoconfiguration [2], the mobile
node may not wish to release the address immediately upon switching node may not wish to release the address immediately upon switching
to a new primary care-of address. to a new primary care-of address.
10.16. Routing Multicast Packets 10.17. Routing Multicast Packets
A mobile node that is connected to its home link functions in the A mobile node that is connected to its home link functions in the
same way as any other (stationary) node. Thus, when it is at home, same way as any other (stationary) node. Thus, when it is at home,
a mobile node functions identically to other multicast senders and a mobile node functions identically to other multicast senders and
receivers. This section therefore describes the behavior of a mobile receivers. This section therefore describes the behavior of a mobile
node that is not on its home link. node that is not on its home link.
In order to receive packets sent to some multicast group, a mobile In order to receive packets sent to some multicast group, a mobile
node must join that multicast group. One method by which a mobile node must join that multicast group. One method by which a mobile
node MAY join the group is via a (local) multicast router on the node MAY join the group is via a (local) multicast router on the
skipping to change at page 82, line 5 skipping to change at page 85, line 13
node. node.
A mobile node that wishes to send packets to a multicast group A mobile node that wishes to send packets to a multicast group
also has two options: (1) send directly on the foreign link being also has two options: (1) send directly on the foreign link being
visited; or (2) send via a tunnel to its home agent. Because visited; or (2) send via a tunnel to its home agent. Because
multicast routing in general depends upon the Source Address used in multicast routing in general depends upon the Source Address used in
the IPv6 header of the multicast packet, a mobile node that tunnels a the IPv6 header of the multicast packet, a mobile node that tunnels a
multicast packet to its home agent MUST use its home address as the multicast packet to its home agent MUST use its home address as the
IPv6 Source Address of the inner multicast packet. IPv6 Source Address of the inner multicast packet.
10.17. Returning Home 10.18. Returning Home
A mobile node detects that it has returned to its home link through A mobile node detects that it has returned to its home link through
the movement detection algorithm in use (Section 10.3), when the the movement detection algorithm in use (Section 10.4), when the
mobile node detects that its home subnet prefix is again on-link. mobile node detects that its home subnet prefix is again on-link.
The mobile node SHOULD then send a Binding Update to its home agent, The mobile node SHOULD then send a Binding Update to its home agent,
to instruct its home agent to no longer intercept or tunnel packets to instruct its home agent to no longer intercept or tunnel packets
for it. In this Binding Update, the mobile node MUST set the care-of for it. In this Binding Update, the mobile node MUST set the care-of
address for the binding (the Source Address field in the packet's address for the binding (the Source Address field in the packet's
IPv6 header) to the mobile node's own home address. As with other IPv6 header) to the mobile node's own home address. As with other
Binding Updates sent to register with its home agent, the mobile Binding Updates sent to register with its home agent, the mobile
node MUST set the Acknowledge (A) and Home Registration (H) bits, node MUST set the Acknowledge (A) and Home Registration (H) bits,
and SHOULD retransmit the Binding Update until a matching Binding and SHOULD retransmit the Binding Update until a matching Binding
Acknowledgement is received. Acknowledgement is received.
skipping to change at page 84, line 32 skipping to change at page 87, line 32
- The Advertisement Interval option, described in Section 6.3. - The Advertisement Interval option, described in Section 6.3.
- The Home Agent Information option, described in Section 6.4. - The Home Agent Information option, described in Section 6.4.
Finally, this document defines a new type of anycast address, which Finally, this document defines a new type of anycast address, which
must be assigned a reserved value for use with any subnet prefix to must be assigned a reserved value for use with any subnet prefix to
define this anycast address on each subnet: define this anycast address on each subnet:
- The "Mobile IPv6 Home-Agents" anycast address [8], used in the - The "Mobile IPv6 Home-Agents" anycast address [8], used in the
dynamic home agent address discovery procedure described in dynamic home agent address discovery procedure described in
Sections 9.2 and 10.6. Sections 9.2 and 10.7.
13. Security Considerations 13. Security Considerations
13.1. Binding Updates, Acknowledgements, and Requests 13.1. Binding Updates, Acknowledgements, and Requests
The Binding Update option described in this document will result The Binding Update option described in this document will result
in packets addressed to a mobile node being delivered instead to in packets addressed to a mobile node being delivered instead to
its care-of address. This ability to change the routing of these its care-of address. This ability to change the routing of these
packets could be a significant vulnerability if any packet containing packets could be a significant vulnerability if any packet containing
a Binding Update option was not authenticated. Such use of "remote a Binding Update option was not authenticated. Such use of "remote
skipping to change at page 88, line 9 skipping to change at page 91, line 9
privacy is desired, the mobile node can create a tunnel to its home privacy is desired, the mobile node can create a tunnel to its home
agent. Then, packets destined for correspondent nodes will appear agent. Then, packets destined for correspondent nodes will appear
to emanate from the home subnet, and it may be more difficult to to emanate from the home subnet, and it may be more difficult to
pinpoint the location of the mobile node. Such mechanisms are all pinpoint the location of the mobile node. Such mechanisms are all
beyond the scope of this document. beyond the scope of this document.
Changes from Previous Version of the Draft Changes from Previous Version of the Draft
This appendix briefly lists some of the major changes in this This appendix briefly lists some of the major changes in this
draft relative to the previous version of this same draft, draft relative to the previous version of this same draft,
draft-ietf-mobileip-ipv6-07.txt: draft-ietf-mobileip-ipv6-08.txt:
- Changed the listed Option Type codes for the destination options - Added a new section (Section 10.2), giving guidance to
and Type codes Router Advertisement options to their official implementors on the interaction between outbound Mobile IP
values, now that IPv6 has finally officially assigned these. processing and outbound IPsec processing for packets sent by a
mobile node while away from home.
- Added a Router (R) bit in the Binding Update option format, for - Changed the optional Care-of Address field in the Binding Update
use in "home registration" Binding Updates. This flag bit tells option format (Section 5.1) to instead be a sub-option. This
the home agent that the mobile node is a router, so that the better matches the use of other sub-options to encode optional
home agent can set the corresponding bit correctly in all proxy information in an option, and also makes the specification of the
Neighbor Advertisements that it sends on behalf of this mobile alignment requirement for the Binding Update option easier.
node. Also added a bit to save this flag in the definition of
the Binding Cache entry format, and defined how it is used in
sending proxy Neighbor Advertisements.
- Added a bit of text in a few places to clarify the meaning of - Also removed the Care-of Address Present (C) bit in the Binding
MAX_UPDATE_RATE. Update option format, as it is no longer needed with the use of a
sub-option to specify the alternate care-of address. NOTE: This
change also resulted in moving the Router (R) bit over by one bit
position in the Binding Update option format.
- Added to Section 7.3 a requirement that every home agent SHOULD - Added explicit specification of the alignment requirements [5]
support a configuration mechanism to allow a system administrator for each of the Mobile IPv6 destination options and sub-options.
to manually set the value to be sent by this home agent in the
Home Agent Preference field of the Home Agent Information Option
in Router Advertisements that it sends.
- Added a suggestion in Section 6.4 that the Home Agent Preference - Introduced Pad1 and PadN sub-options (Section 5.5) to allow
field in a Home Agent Information option being sent by a home the sub-options in Mobile IPv6 options to be aligned properly.
agent could be set dynamically by the sending home agent based To match the option numbering used for the Pad1 and PadN
on factors such as the number of mobile nodes it is currently options defined for use in Hop-by-Hop Options and Destination
serving or the remaining resources it has for serving additional Options extension headers [5], these two sub-options have been
mobile nodes. However, the details of such dynamic settings numbered 0 and 1, respectively. NOTE: This change also resulted
are beyond the scope of this document since they do not involve in changing the sub-option numbers of the other Mobile IPv6
protocol standardization issues. sub-options.
- Normalized all references to the "Mobile IPv6 Home-Agents" - Added an explicit specification of the units in which
anycast address to use the full name of this specific anycast the Lifetime and Refresh fields are expressed in the
address and to point to the new definition of reserved IPv6 Binding Acknowledgement option (Section 5.2). As with the
subnet anycast addresses, RFC 2526. corresponding Lifetime field in the Binding Update option and the
Valid Lifetime and Preferred Lifetime in the Prefix Information
option used by Neighbor Discovery [14], these fields in the
Binding Acknowledgement option are expressed in seconds.
- Updated all references to their most recent versions, including - Rewrote Section 10.9 to indicate that the Binding Update is sent
changing old Internet-Draft references into new RFC references to any home agent on the link on which the specified previous
where available. Changed remaining specific Internet-Draft care-of address is located, rather than (necessarily) to the
references to be generic "Work in progress" references. router that it used as its default router on that link. Also,
the mobile node can establish packet forwarding from any previous
care-of address, not just from its previous primary care-of
address.
- Updated the "Status of This Memo" section to the new official - Removed the Status value of 129 (Poorly formed Binding Update)
version of this text. for the Binding Acknowledgement option, since this value is not
used. Instead, poorly formed Binding Updates have already been
defined (Section 8.2) to be silently discarded.
- Corrected a few minor typographical errors in places. - Removed the Status value of 134 (Sequence Number field value too
small) for the Binding Acknowledgement option, since this value
is not used. Instead, received Binding Updates in which the
Sequence Number field is not greater than the Sequence Number
received in the previous Binding Update for this home address,
if any, have already been defined (Section 8.2) to be silently
discarded.
- Corrected a few more minor typographical errors in places.
Acknowledgements Acknowledgements
We would like to thank the members of the Mobile IP and IPng Working We would like to thank the members of the Mobile IP and IPng
Groups for their comments and suggestions on this work. We would Working Groups for their comments and suggestions on this work.
particularly like to thank (in alphabetical order) Josh Broch We would particularly like to thank (in alphabetical order)
(Carnegie Mellon University), Thomas Narten (IBM), Erik Nordmark (Sun Josh Broch (Carnegie Mellon University), Rich Draves (Microsoft
Microsystems), Simon Nybroe (Telebit Communications), Patrice Romand Research), Jun-Ichiro Hagino (IIJ Research Laboratory), Thomas Narten
(Bull S.A.), Tom Soderlund (Nokia Research), and Jim Solomon (RedBack (IBM), Erik Nordmark (Sun Microsystems), Simon Nybroe (Telebit
Networks) for their detailed reviews of earlier versions of this Communications), Patrice Romand (Bull S.A.), Tom Soderlund (Nokia
draft. Their suggestions have helped to improve both the design and Research), and Jim Solomon (RedBack Networks) for their detailed
presentation of the protocol. reviews of earlier versions of this draft. Their suggestions have
helped to improve both the design and presentation of the protocol.
References References
[1] S. M. Bellovin. Security problems in the TCP/IP protocol suite. [1] S. M. Bellovin. Security problems in the TCP/IP protocol suite.
ACM Computer Communications Review, 19(2), March 1989. ACM Computer Communications Review, 19(2), March 1989.
[2] Jim Bound and Charles Perkins. Dynamic Host Configuration [2] Jim Bound and Charles Perkins. Dynamic Host Configuration
Protocol for IPv6 (DHCPv6), February 1999. Work in progress. Protocol for IPv6 (DHCPv6), February 1999. Work in progress.
[3] Scott Bradner. Key words for use in RFCs to indicate [3] Scott Bradner. Key words for use in RFCs to indicate
skipping to change at page 91, line 29 skipping to change at page 94, line 29
[5] Stephen E. Deering and Robert M. Hinden. Internet Protocol [5] Stephen E. Deering and Robert M. Hinden. Internet Protocol
version 6 (IPv6) specification. RFC 2460, December 1998. version 6 (IPv6) specification. RFC 2460, December 1998.
[6] Paul Ferguson and Daniel Senie. Network ingress filtering: [6] Paul Ferguson and Daniel Senie. Network ingress filtering:
Defeating denial of service attacks which employ IP source Defeating denial of service attacks which employ IP source
address spoofing. RFC 2267, January 1998. address spoofing. RFC 2267, January 1998.
[7] Robert M. Hinden and Stephen E. Deering. IP Version 6 [7] Robert M. Hinden and Stephen E. Deering. IP Version 6
addressing architecture. RFC 2373, July 1998. addressing architecture. RFC 2373, July 1998.
[8] David B. Johnson and Stephen E. Deering. Reserved ipv6 subnet [8] David B. Johnson and Stephen E. Deering. Reserved IPv6 subnet
anycast addresses. RFC 2526, March 1999. anycast addresses. RFC 2526, March 1999.
[9] Stephen Kent and Randall Atkinson. IP Authentication header. [9] Stephen Kent and Randall Atkinson. IP Authentication header.
RFC 2402, November 1998. RFC 2402, November 1998.
[10] Stephen Kent and Randall Atkinson. IP Encapsulating Security [10] Stephen Kent and Randall Atkinson. IP Encapsulating Security
Payload (ESP). RFC 2406, November 1998. Payload (ESP). RFC 2406, November 1998.
[11] Stephen Kent and Randall Atkinson. Security architecture for [11] Stephen Kent and Randall Atkinson. Security architecture for
the Internet Protocol. RFC 2401, November 1998. the Internet Protocol. RFC 2401, November 1998.
skipping to change at page 92, line 25 skipping to change at page 95, line 25
Or converting network protocol addresses to 48.bit Ethernet Or converting network protocol addresses to 48.bit Ethernet
addresses for transmission on Ethernet hardware. RFC 826, addresses for transmission on Ethernet hardware. RFC 826,
November 1982. November 1982.
[20] J. B. Postel. User Datagram Protocol. RFC 768, August 1980. [20] J. B. Postel. User Datagram Protocol. RFC 768, August 1980.
[21] J. B. Postel, editor. Transmission Control Protocol. RFC 793, [21] J. B. Postel, editor. Transmission Control Protocol. RFC 793,
September 1981. September 1981.
[22] Joyce K. Reynolds and Jon Postel. Assigned numbers. RFC 1700, [22] Joyce K. Reynolds and Jon Postel. Assigned numbers. RFC 1700,
October 1994. October 1994. See also http://www.iana.org/numbers.html.
[23] Susan Thomson and Thomas Narten. IPv6 stateless address [23] Susan Thomson and Thomas Narten. IPv6 stateless address
autoconfiguration. RFC 2462, December 1998. autoconfiguration. RFC 2462, December 1998.
Chair's Address Chair's Address
The Working Group can be contacted via its current chairs: The Working Group can be contacted via its current chairs:
Erik Nordmark Phil Roberts
Sun Microsystems, Inc. Motorola
2550 Garcia Avenue 1501 West Shure Drive
Mt. View, CA 94041 Arlington Heights, IL 60004
USA
Phone: +1 415 786-5166 Phone: +1 847 632-3148
Fax: +1 415 786-5896 E-mail: qa3445@email.mot.com
E-mail: nordmark@sun.com
Basavaraj Patil Basavaraj Patil
Nortel Networks, Inc. Nortel Networks, Inc.
2201 Lakeside Blvd. 2201 Lakeside Blvd.
Richardson, TX 75082-4399 Richardson, TX 75082-4399
USA USA
Phone: +1 972 684-1489 Phone: +1 972 684-1489
Fax: +1 972 685-3207
E-mail: bpatil@nortelnetworks.com E-mail: bpatil@nortelnetworks.com
Authors' Addresses Authors' Addresses
Questions about this document can also be directed to the authors: Questions about this document can also be directed to the authors:
David B. Johnson David B. Johnson
Carnegie Mellon University Carnegie Mellon University
Computer Science Department Computer Science Department
5000 Forbes Avenue 5000 Forbes Avenue
Pittsburgh, PA 15213-3891 Pittsburgh, PA 15213-3891
USA USA
Phone: +1 412 268-7399 Phone: +1 412 268-7399
Fax: +1 412 268-5576 Fax: +1 412 268-5576
E-mail: dbj@cs.cmu.edu E-mail: dbj@cs.cmu.edu
Charles Perkins Charles Perkins
Sun Microsystems, Inc. Nokia
Technology Development Group 313 Fairchild Drive
Mail Stop MPK15-214 Mountain View, CA 94043
Room 2682
901 San Antonio Road
Palo Alto, CA 94303
USA USA
Phone: +1 415 786-6464 Phone: +1 650 625-2986
Fax: +1 415 786-6445 Fax: +1 650 691-2170
E-mail: cperkins@eng.sun.com E-mail: charliep@iprg.nokia.com
 End of changes. 

This html diff was produced by rfcdiff 1.25, available from http://www.levkowetz.com/ietf/tools/rfcdiff/