draft-ietf-ipngwg-icmp-v3-03.txt   draft-ietf-ipngwg-icmp-v3-04.txt 
Internet Draft A. Conta, Transwitch Internet Draft A. Conta, Transwitch
IPv6 Working Group S. Deering, Cisco Systems IPv6 Working Group S. Deering, Cisco Systems
February 15, 2004 1 June 2004
Internet Control Message Protocol (ICMPv6) Internet Control Message Protocol (ICMPv6)
for the Internet Protocol Version 6 (IPv6) for the Internet Protocol Version 6 (IPv6)
Specification Specification
<draft-ietf-ipngwg-icmp-v3-03.txt> <draft-ietf-ipngwg-icmp-v3-04.txt>
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with By submitting this Internet-Draft, I certify that any applicable
all provisions of Section 10 of RFC2026. patent or other IPR claims of which I am aware have been disclosed,
and any of which I become aware will be disclosed, in accordance with
RFC 3668.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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This internet draft will expire on August 20, 2004. This internet draft will expire on December 4, 2004.
Abstract Abstract
This document describes the format of a set of control messages used This document describes the format of a set of control messages used
in ICMPv6 (Internet Control Message Protocol). ICMPv6 is the in ICMPv6 (Internet Control Message Protocol). ICMPv6 is the
Internet Control Message Protocol for Internet Protocol version 6 Internet Control Message Protocol for Internet Protocol version 6
(IPv6). (IPv6).
Table of Contents Table of Contents
1. Introduction........................................3 1. Introduction.....................................................3
2. ICMPv6 (ICMP for IPv6)..............................3 2. ICMPv6 (ICMP for IPv6)...........................................3
2.1 Message General Format.......................3 2.1 Message General Format....................................3
2.2 Message Source Address Determination.........5 2.2 Message Source Address Determination......................5
2.3 Message Checksum Calculation.................6 2.3 Message Checksum Calculation..............................6
2.4 Message Processing Rules.....................6 2.4 Message Processing Rules..................................6
3. ICMPv6 Error Messages...............................9 3. ICMPv6 Error Messages............................................9
3.1 Destination Unreachable Message..............9 3.1 Destination Unreachable Message...........................9
3.2 Packet Too Big Message......................11 3.2 Packet Too Big Message...................................12
3.3 Time Exceeded Message.......................12 3.3 Time Exceeded Message....................................13
3.4 Parameter Problem Message...................14 3.4 Parameter Problem Message................................15
4. ICMPv6 Informational Messages......................16 4. ICMPv6 Informational Messages...................................17
4.1 Echo Request Message........................16 4.1 Echo Request Message.....................................17
4.2 Echo Reply Message..........................17 4.2 Echo Reply Message.......................................18
5. Security Considerations............................19 5. Security Considerations.........................................20
6. IANA Considerations................................21 5.1 Authentication and Confidentiality of ICMP messages......20
7. References.........................................21 5.2 ICMP Attacks.............................................20
7.1 Normative...................................21 6. IANA Considerations.............................................21
7.2 Informative.................................22 6.1 Procedure for new ICMPV6 Type and Code value assignments.22
8. Acknowledgments....................................22 6.2 Assignments for this document............................22
9. Authors' Addresses.................................22 7. References......................................................23
Appendix A - Changes since RFC 2463...................22 7.1 Normative................................................23
7.2 Informative..............................................24
8. Acknowledgments.................................................24
9. Authors' Addresses..............................................24
Appendix A - Changes since RFC 2463................................24
1. Introduction 1. Introduction
The Internet Protocol, version 6 (IPv6) is a new version of IP. IPv6 The Internet Protocol, version 6 (IPv6) is a new version of IP. IPv6
uses the Internet Control Message Protocol (ICMP) as defined for IPv4 uses the Internet Control Message Protocol (ICMP) as defined for IPv4
[RFC-792], with a number of changes. The resulting protocol is [RFC-792], with a number of changes. The resulting protocol is
called ICMPv6, and has an IPv6 Next Header value of 58. called ICMPv6, and has an IPv6 Next Header value of 58.
This document describes the format of a set of control messages used This document describes the format of a set of control messages used
in ICMPv6. It does not describe the procedures for using these in ICMPv6. It does not describe the procedures for using these
skipping to change at page 4, line 12 skipping to change at page 4, line 12
This document defines the message formats for the following ICMPv6 This document defines the message formats for the following ICMPv6
messages: messages:
ICMPv6 error messages: ICMPv6 error messages:
1 Destination Unreachable (see section 3.1) 1 Destination Unreachable (see section 3.1)
2 Packet Too Big (see section 3.2) 2 Packet Too Big (see section 3.2)
3 Time Exceeded (see section 3.3) 3 Time Exceeded (see section 3.3)
4 Parameter Problem (see section 3.4) 4 Parameter Problem (see section 3.4)
100 Private experimentation
101 Private experimentation
ICMPv6 informational messages: ICMPv6 informational messages:
128 Echo Request (see section 4.1) 128 Echo Request (see section 4.1)
129 Echo Reply (see section 4.2) 129 Echo Reply (see section 4.2)
200 Private experimentation
201 Private experimentation
255 Reserved for expansion
Type values 100, 101, 200, and 201 are reserved for private
experimentation. These are not intended for general use. It is
expected that multiple concurrent experiments will be done with the
same type values. Any wide scale and/or uncontrolled usage should
obtain real allocations as defined in section 6.
Type value 255 is reserved for future expansion of the type value
range if there should be a shortage in the future. The details of
this are left for future work. One possible way of doing this that
would not cause any problems with current implementations is if the
type equals 255, use the code field for the new assignment. Existing
implementations would ignore the new assignments as specified in
section 2.4, section (b). The new messages using these expanded type
values, could assign fields in the message body for it's code values.
Every ICMPv6 message is preceded by an IPv6 header and zero or more Every ICMPv6 message is preceded by an IPv6 header and zero or more
IPv6 extension headers. The ICMPv6 header is identified by a Next IPv6 extension headers. The ICMPv6 header is identified by a Next
Header value of 58 in the immediately preceding header. (NOTE: this Header value of 58 in the immediately preceding header. (NOTE: this
is different than the value used to identify ICMP for IPv4.) is different than the value used to identify ICMP for IPv4.)
The ICMPv6 messages have the following general format: The ICMPv6 messages have the following general format:
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+ Message Body + + Message Body +
| | | |
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| type-specific data (32 bits) | | type-specific data (32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| As much of invoking packet | | As much of invoking packet |
+ as will fit without the ICMPv6 packet + + as will fit without the ICMPv6 packet +
| exceeding the minimum IPv6 MTU [IPv6] | | exceeding the minimum IPv6 MTU [IPv6] |
2.2 Message Source Address Determination 2.2 Message Source Address Determination
A node that sends an ICMPv6 message has to determine both the Source A node that sends an ICMPv6 message has to determine both the Source
and Destination IPv6 Addresses in the IPv6 header before calculating and Destination IPv6 Addresses in the IPv6 header before calculating
the checksum. If the node has more than one unicast address, it must the checksum. If the node has more than one unicast address, it MUST
choose the Source Address of the message as follows: choose the Source Address of the message as follows:
(a) If the message is a response to a message sent to one of the (a) If the message is a response to a message sent to one of the
node's unicast addresses, the Source Address of the reply must node's unicast addresses, the Source Address of the reply MUST
be that same address. be that same address.
(b) If the message is a response to a message sent to a multicast or (b) If the message is a response to a message sent to a multicast or
anycast group in which the node is a member, the Source Address anycast group in which the node is a member, the Source Address
of the reply must be a unicast address belonging to the of the reply MUST be a unicast address belonging to the
interface on which the multicast or anycast packet was received. interface on which the multicast or anycast packet was received.
(c) If the message is a response to a message sent to an address (c) If the message is a response to a message sent to an address
that does not belong to the node, the Source Address should be that does not belong to the node, the Source Address SHOULD be
that unicast address belonging to the node that will be most that unicast address belonging to the node that will be most
helpful in diagnosing the error. For example, if the message is helpful in diagnosing the error. For example, if the message is
a response to a packet forwarding action that cannot complete a response to a packet forwarding action that cannot complete
successfully, the Source Address should be a unicast address successfully, the Source Address SHOULD be a unicast address
belonging to the interface on which the packet forwarding belonging to the interface on which the packet forwarding
failed. failed.
(d) Otherwise, the node's routing table must be examined to (d) Otherwise, the node's routing table must be examined to
determine which interface will be used to transmit the message determine which interface will be used to transmit the message
to its destination, and a unicast address belonging to that to its destination, and a unicast address belonging to that
interface must be used as the Source Address of the message. interface MUST be used as the Source Address of the message.
2.3 Message Checksum Calculation 2.3 Message Checksum Calculation
The checksum is the 16-bit one's complement of the one's complement The checksum is the 16-bit one's complement of the one's complement
sum of the entire ICMPv6 message starting with the ICMPv6 message sum of the entire ICMPv6 message starting with the ICMPv6 message
type field, prepended with a "pseudo-header" of IPv6 header fields, type field, prepended with a "pseudo-header" of IPv6 header fields,
as specified in [IPv6, section 8.1]. The Next Header value used in as specified in [IPv6, section 8.1]. The Next Header value used in
the pseudo-header is 58. (NOTE: the inclusion of a pseudo-header in the pseudo-header is 58. (NOTE: the inclusion of a pseudo-header in
the ICMPv6 checksum is a change from IPv4; see [IPv6] for the the ICMPv6 checksum is a change from IPv4; see [IPv6] for the
rationale for this change.) rationale for this change.)
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Implementations MUST observe the following rules when processing Implementations MUST observe the following rules when processing
ICMPv6 messages (from [RFC-1122]): ICMPv6 messages (from [RFC-1122]):
(a) If an ICMPv6 error message of unknown type is received, it MUST (a) If an ICMPv6 error message of unknown type is received, it MUST
be passed to the upper layer. be passed to the upper layer.
(b) If an ICMPv6 informational message of unknown type is received, (b) If an ICMPv6 informational message of unknown type is received,
it MUST be silently discarded. it MUST be silently discarded.
(c) Every ICMPv6 error message (type < 128) includes as much of the (c) Every ICMPv6 error message (type < 128) MUST include as much of
IPv6 offending (invoking) packet (the packet that caused the the IPv6 offending (invoking) packet (the packet that caused the
error) as will fit without making the error message packet error) as will fit without making the error message packet
exceed the minimum IPv6 MTU [IPv6]. exceed the minimum IPv6 MTU [IPv6].
(d) In those cases where the internet-layer protocol is required to (d) In those cases where the internet-layer protocol is required to
pass an ICMPv6 error message to the upper-layer process, the pass an ICMPv6 error message to the upper-layer process, the
upper-layer protocol type is extracted from the original packet upper-layer protocol type is extracted from the original packet
(contained in the body of the ICMPv6 error message) and used to (contained in the body of the ICMPv6 error message) and used to
select the appropriate upper-layer process to handle the error. select the appropriate upper-layer process to handle the error.
If the original packet had an unusually large amount of If the original packet had an unusually large amount of
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(e.5) a packet sent as a link-layer broadcast, (the exception (e.5) a packet sent as a link-layer broadcast, (the exception
from e.3 applies to this case too), or from e.3 applies to this case too), or
(e.6) a packet whose source address does not uniquely identify (e.6) a packet whose source address does not uniquely identify
a single node -- e.g., the IPv6 Unspecified Address, an a single node -- e.g., the IPv6 Unspecified Address, an
IPv6 multicast address, or an address known by the ICMP IPv6 multicast address, or an address known by the ICMP
message sender to be an IPv6 anycast address. message sender to be an IPv6 anycast address.
(f) Finally, in order to limit the bandwidth and forwarding costs (f) Finally, in order to limit the bandwidth and forwarding costs
incurred sending ICMPv6 error messages, an IPv6 node MUST limit incurred by sending ICMPv6 error messages, an IPv6 node MUST
the rate of ICMPv6 error messages it sends. This situation may limit the rate of ICMPv6 error messages it sends. This
occur when a source sending a stream of erroneous packets fails situation may occur when a source sending a stream of erroneous
to heed the resulting ICMPv6 error messages. packets fails to heed the resulting ICMPv6 error messages.
A recommended method for implementing the rate-limiting function A recommended method for implementing the rate-limiting function
is a token bucket, limiting the average rate of transmission to is a token bucket, limiting the average rate of transmission to
N, where N can either be packets/second or a fraction of the N, where N can either be packets/second or a fraction of the
attached link's bandwidth, but allowing up to B error messages attached link's bandwidth, but allowing up to B error messages
to be transmitted in a burst, as long as the long-term average to be transmitted in a burst, as long as the long-term average
is not exceeded. is not exceeded.
Rate-limiting mechanisms which cannot cope with bursty traffic Rate-limiting mechanisms which cannot cope with bursty traffic
(e.g., traceroute) are not recommended; for example a simple (e.g., traceroute) are not recommended; for example a simple
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If the reason for the failure to deliver is that the destination is If the reason for the failure to deliver is that the destination is
beyond the scope of the source address, the Code field is set to 2. beyond the scope of the source address, the Code field is set to 2.
This condition can occur only when the scope of the source address is This condition can occur only when the scope of the source address is
smaller than the scope of the destination address (e.g., when a smaller than the scope of the destination address (e.g., when a
packet has a link-local source address and a global-scope destination packet has a link-local source address and a global-scope destination
address) and the packet cannot be delivered to the destination address) and the packet cannot be delivered to the destination
without leaving the scope of the source address. without leaving the scope of the source address.
If the reason for the failure to deliver can not be mapped to any of If the reason for the failure to deliver can not be mapped to any of
the specific codes listed above, the Code field is set to 3. The other codes, the Code field is set to 3. The example of such cases
example of such cases are inability to resolve the IPv6 destination are inability to resolve the IPv6 destination address into a
address into a corresponding link address, or a link-specific problem corresponding link address, or a link-specific problem of some sort.
of some sort.
One specific case in which a Destination Unreachable message with a One specific case in which a Destination Unreachable message with a
code 3 is sent is in response to a packet received by a router from a code 3 is sent is in response to a packet received by a router from a
point-to-point link, destined to an address within a subnet assigned point-to-point link, destined to an address within a subnet assigned
to that same link (other than one of the receiving router's own to that same link (other than one of the receiving router's own
addresses). In such a case, the packet MUST NOT be forwarded back addresses). In such a case, the packet MUST NOT be forwarded back
onto the arrival link. onto the arrival link.
A destination node SHOULD send a Destination Unreachable message with A destination node SHOULD send a Destination Unreachable message with
Code 4 in response to a packet for which the transport protocol Code 4 in response to a packet for which the transport protocol
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If the reason for the failure to deliver is that packet with this If the reason for the failure to deliver is that packet with this
source address is not allowed due to ingress or egress filtering source address is not allowed due to ingress or egress filtering
policies, the Code field is set to 5. policies, the Code field is set to 5.
If the reason for the failure to deliver is that the route to the If the reason for the failure to deliver is that the route to the
destination is a reject route, the Code field is set to 6. This may destination is a reject route, the Code field is set to 6. This may
occur if the router has been configured to reject all the traffic for occur if the router has been configured to reject all the traffic for
a specific prefix. a specific prefix.
Codes 5 and 6 are more informative subsets of code 1.
Upper layer notification Upper layer notification
A node receiving the ICMPv6 Destination Unreachable message MUST A node receiving the ICMPv6 Destination Unreachable message MUST
notify the upper-layer process. notify the upper-layer process.
3.2 Packet Too Big Message 3.2 Packet Too Big Message
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Header or IP Encapsulating Security Payload Header exists for the Header or IP Encapsulating Security Payload Header exists for the
destination address. The security associations may have been created destination address. The security associations may have been created
through manual configuration or through the operation of some key through manual configuration or through the operation of some key
management protocol. management protocol.
Received ICMP packets that have Authentication Header or Received ICMP packets that have Authentication Header or
Encapsulating Security Payload Header must be processed as specified Encapsulating Security Payload Header must be processed as specified
in [IPv6-AUTH] and [IPv6-ESP]. The ICMP packets that fail the in [IPv6-AUTH] and [IPv6-ESP]. The ICMP packets that fail the
security processing MUST be ignored and discarded. security processing MUST be ignored and discarded.
It SHOULD be possible for the system administrator to configure a The system administrator MAY be allowed to configure a node to ignore
node to ignore any ICMP messages that are not authenticated using any ICMP messages that are not authenticated using either the
either the Authentication Header or Encapsulating Security Payload. Authentication Header or Encapsulating Security Payload. If
Such a switch SHOULD default to allowing unauthenticated messages. provided, such a switch SHOULD default to allowing unauthenticated
messages. Note that setting up Security Associations to deal with
all the required ICMP packets is a very difficult task (e.g.,
consider the Path MTU Discovery packets). So Path MTU Discovery (and
possibly some others) may not work if the node only allows
authenticated ICMP packets.
5.2 ICMP Attacks 5.2 ICMP Attacks
ICMP messages may be subject to various attacks. A complete ICMP messages may be subject to various attacks. A complete
discussion can be found in the IP Security Architecture [IPv6-SA]. A discussion can be found in the IP Security Architecture [IPv6-SA]. A
brief discussion of such attacks and their prevention is as follows: brief discussion of such attacks and their prevention is as follows:
1. ICMP messages may be subject to actions intended to cause the 1. ICMP messages may be subject to actions intended to cause the
receiver to believe the message came from a different source than receiver to believe the message came from a different source than
the message originator. The protection against this attack can be the message originator. The protection against this attack can be
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multicast routers does require the malicious node to be part of multicast routers does require the malicious node to be part of
the correct multicast path i.e. near to the multicast source. the correct multicast path i.e. near to the multicast source.
This attack can only be avoided by securing the multicast traffic. This attack can only be avoided by securing the multicast traffic.
The multicast source should be careful while sending multicast The multicast source should be careful while sending multicast
traffic with the destination options marked as mandatory because traffic with the destination options marked as mandatory because
they can cause a denial of service attack to themselves if the they can cause a denial of service attack to themselves if the
destination option is unknown to a large number of destinations. destination option is unknown to a large number of destinations.
6. IANA Considerations 6. IANA Considerations
IANA considerations for the values of ICMPv6 type and code are given 6.1 Procedure for new ICMPV6 Type and Code value assignments
in [RFC-2780].
ICMPv6 type 1 "Destination Unreachable" code 2 that was unassigned in The IPv6 ICMP header [ICMPV6] contains the following fields that
[RFC-2463], has been assigned to "beyond scope of source address" carry values assigned from IANA-managed name spaces: Type and Code.
message. Code field values are defined relative to a specific Type value.
IANA is requested to assign the following two new codes for ICMPv6 Values for the IPv6 ICMP Type fields are allocated using the
type 1 "Destination Unreachable". following procedure:
1. The IANA should allocate and permanently register new ICMPv6 type
codes from IETF RFC publication. This is for all RFC types
including standards track, informational, experimental status,
etc.
2. IETF working groups with working group consensus and area director
approval can request reclaimable ICMPV6 type code assignments from
the IANA. The IANA will tag the values as "reclaimable in
future".
The "reclaimable in the future" tag will be removed when an is
published documenting the protocol as defined in 1). This will
make the assignment permanent.
At the point where the type values are 85% assigned, the IANA will
request that the IETF review the assignments tagged "reclaimable
in the future" and make a recommendation to the IANA which ones
can be reclaimed and reassigned.
3. Requests for type value assignments from outside of the IETF
should be sent to the IETF for review. The general guideline for
this review is that the assignment should be made if there is
public and open documentation of the protocol and if the
assignment is not being used to circumvent an existing IETF
protocol or work in progress.
The policy for assigning Code values for new IPv6 ICMP Types should
be defined in the document defining the new Type values.
6.2 Assignments for this document
The following should update the assignments located at:
http://www.iana.org/assignments/icmpv6-parameters
The IANA is requested to reassign ICMPv6 type 1 "Destination
Unreachable" code 2, that was unassigned in [RFC-2463], to:
2 - beyond scope of source address
The IANA is requested to assign the following two new codes values
for ICMPv6 type 1 "Destination Unreachable":
5 - source address failed ingress/egress policy 5 - source address failed ingress/egress policy
6 - reject route to destination 6 - reject route to destination
The IANA is requested to assign the following new type values:
100 Private experimentation
101 Private experimentation
200 Private experimentation
201 Private experimentation
255 Reserved for expansion
7. References 7. References
7.1 Normative 7.1 Normative
[IPv6] Deering, S., R. Hinden, "Internet Protocol, Version 6, [IPv6] Deering, S., R. Hinden, "Internet Protocol, Version 6,
Specification", RFC2460, December 1998. Specification", RFC2460, December 1998.
[IPv6-ADDR] Hinden, R., S. Deering, "IP Version 6 Addressing
Architecture", RFC2373, July 1998.
[IPv6-DISC] Narten, T., E. Nordmark, W. Simpson, "Neighbor Discovery [IPv6-DISC] Narten, T., E. Nordmark, W. Simpson, "Neighbor Discovery
for IP Version 6 (IPv6)", RFC2461, December, 1998. for IP Version 6 (IPv6)", RFC2461, December, 1998.
[RFC-792] Postel, J., "Internet Control Message Protocol", STD 5, [RFC-792] Postel, J., "Internet Control Message Protocol", STD 5,
RFC792, September 1981. RFC792, September 1981.
[RFC-2463] Conta, A., S. Deering, "Internet Control Message [RFC-2463] Conta, A., S. Deering, "Internet Control Message
Protocol (ICMPv6) for the Internet Protocol Version 6 Protocol (ICMPv6) for the Internet Protocol Version 6
(IPv6) Specification", RFC2463, December, 1998. (IPv6) Specification", RFC2463, December, 1998.
[RFC-1122] Braden, R., "Requirements for Internet Hosts - [RFC-1122] Braden, R., "Requirements for Internet Hosts -
Communication Layers", STD 5, RFC1122, August 1989. Communication Layers", STD 5, RFC1122, August 1989.
[PMTU] McCann, J., S. Deering, J. Mogul, "Path MTU Discovery
for IP version 6", RFC1981, August 1996.
[RFC-2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC-2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP14, RFC2119, March 1997. Requirement Levels", BCP14, RFC2119, March 1997.
7.2 Informative
[RFC-2780] Bradner, S., V. Paxson, "IANA Allocation Guidelines For
Values In the Internet Protocol and Related Headers",
RFC 2780, March 2000.
[IPv6-ADDR] Hinden, R., S. Deering, "IP Version 6 Addressing
Architecture", RFC2373, July 1998.
[PMTU] McCann, J., S. Deering, J. Mogul, "Path MTU Discovery
for IP version 6", RFC1981, August 1996.
[IPv6-SA] Kent, S., R. Atkinson, "Security Architecture for the [IPv6-SA] Kent, S., R. Atkinson, "Security Architecture for the
Internet Protocol", RFC1825, November 1998. Internet Protocol", RFC1825, November 1998.
[IPv6-AUTH] Kent, S., R. Atkinson, "IP Authentication Header", RFC [IPv6-AUTH] Kent, S., R. Atkinson, "IP Authentication Header", RFC
2402, November 1998. 2402, November 1998.
[IPv6-ESP] Kent, S., R. Atkinson, "IP Encapsulating Security [IPv6-ESP] Kent, S., R. Atkinson, "IP Encapsulating Security
Payload (ESP)", RFC 2406, November 1998. Payload (ESP)", RFC 2406, November 1998.
7.2 Informative
[RFC-2780] Bradner, S., V. Paxson, "IANA Allocation Guidelines For
Values In the Internet Protocol and Related Headers",
RFC 2780, March 2000.
8. Acknowledgments 8. Acknowledgments
The document is derived from previous ICMP drafts of the SIPP and The document is derived from previous ICMP drafts of the SIPP and
IPng working group. IPng working group.
The IPng working group and particularly Robert Elz, Jim Bound, Bill The IPng working group and particularly Robert Elz, Jim Bound, Bill
Simpson, Thomas Narten, Charlie Lynn, Bill Fink, Scott Bradner, Simpson, Thomas Narten, Charlie Lynn, Bill Fink, Scott Bradner,
Dimitri Haskin, Bob Hinden, Jun-ichiro Itojun Hagino, Tatuya Jinmei, Dimitri Haskin, Bob Hinden, Jun-ichiro Itojun Hagino, Tatuya Jinmei,
Brian Zill, Pekka Savola, and Fred Templin (in chronological order) Brian Zill, Pekka Savola, and Fred Templin (in chronological order)
provided extensive review information and feedback. provided extensive review information and feedback.
skipping to change at page 23, line 25 skipping to change at page 24, line 30
addresses belong to the link itself ("anti-ping-ponging" rule). addresses belong to the link itself ("anti-ping-ponging" rule).
- Added description of Time Exceeded Code 1 (fragment reassembly - Added description of Time Exceeded Code 1 (fragment reassembly
timeout). timeout).
- Added "beyond scope of source address", "source address failed - Added "beyond scope of source address", "source address failed
ingress/egress policy", and "reject route to destination" messages ingress/egress policy", and "reject route to destination" messages
to the family of "unreachable destination" type ICMP error to the family of "unreachable destination" type ICMP error
messages (section 3.1). messages (section 3.1).
- Reserved some ICMP type values for experimentation.
- Added a NOTE in section 2.4, that specifies ICMP message - Added a NOTE in section 2.4, that specifies ICMP message
processing rules precedence. processing rules precedence.
- Added ICMP REDIRECT to the list in Section 2.4 e) of cases in - Added ICMP REDIRECT to the list in Section 2.4 e) of cases in
which ICMP error messages are not to be generated. which ICMP error messages are not to be generated.
- Made minor editorial changes in Section 2.3 on checksum - Made minor editorial changes in Section 2.3 on checksum
calculation, and in Section 5.2. calculation, and in Section 5.2.
- Clarified in section 4.2, regarding the Echo Reply Message, that - Clarified in section 4.2, regarding the Echo Reply Message, that
the source address of an Echo Reply to an anycast Echo Request the source address of an Echo Reply to an anycast Echo Request
should be a unicast address, as in the case of multicast. should be a unicast address, as in the case of multicast.
- Revised the Security Considerations section. Added the use of - Revised the Security Considerations section. Added the use of
Encapsulating Security Payload Header for authentication. Encapsulating Security Payload Header for authentication. Changed
the requirement of an option of "not allowing unauthenticated ICMP
messages" to MAY from SHOULD.
- Added a new attack in the list of possible ICMP attacks in section - Added a new attack in the list of possible ICMP attacks in section
5.2. 5.2.
- Separated References into Normative and Informative. - Separated References into Normative and Informative.
- Added reference to RFC-2780 "IANA Allocation Guidelines For Values - Added reference to RFC-2780 "IANA Allocation Guidelines For Values
In the Internet Protocol and Related Headers" In the Internet Protocol and Related Headers"
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