draft-ietf-mpls-p2mp-lsp-ping-07.txt   draft-ietf-mpls-p2mp-lsp-ping-08.txt 
Network Working Group A. Farrel (Editor) Network Working Group A. Farrel (Editor)
Internet-Draft Old Dog Consulting Internet-Draft Old Dog Consulting
Intended Status: Standards Track S. Yasukawa Intended Status: Standards Track S. Yasukawa
Updates: RFC4379 NTT Updates: RFC4379 NTT
Created: September 10, 2008 Created: August 11, 2009
Expires: March 10, 2009 Expires: February 11, 2010
Detecting Data Plane Failures in Point-to-Multipoint Multiprotocol Detecting Data Plane Failures in Point-to-Multipoint Multiprotocol
Label Switching (MPLS) - Extensions to LSP Ping Label Switching (MPLS) - Extensions to LSP Ping
draft-ietf-mpls-p2mp-lsp-ping-07.txt draft-ietf-mpls-p2mp-lsp-ping-08.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any This Internet-Draft is submitted to IETF in full conformance with the
applicable patent or other IPR claims of which he or she is aware provisions of BCP 78 and BCP 79.
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
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 that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as 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 months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference 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."
skipping to change at page 2, line 5 skipping to change at page 1, line 52
used to detect data plane failures in point-to-point (P2P) MPLS LSPs used to detect data plane failures in point-to-point (P2P) MPLS LSPs
has been recognized and has led to the development of techniques has been recognized and has led to the development of techniques
for fault detection and isolation commonly referred to as "LSP Ping". for fault detection and isolation commonly referred to as "LSP Ping".
The scope of this document is fault detection and isolation for P2MP The scope of this document is fault detection and isolation for P2MP
MPLS LSPs. This documents does not replace any of the mechanisms of MPLS LSPs. This documents does not replace any of the mechanisms of
LSP Ping, but clarifies their applicability to MPLS P2MP LSPs, and LSP Ping, but clarifies their applicability to MPLS P2MP LSPs, and
extends the techniques and mechanisms of LSP Ping to the MPLS P2MP extends the techniques and mechanisms of LSP Ping to the MPLS P2MP
environment. environment.
Conventions used in this document Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.
Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
Contents Contents
1. Introduction ................................................... 4 1. Introduction.................................................... 4
1.1 Design Considerations ......................................... 5 1.1 Design Considerations.......................................... 5
2. Notes on Motivation ............................................ 6 2. Notes on Motivation............................................. 6
2.1. Basic Motivations for LSP Ping ............................... 6 2.1. Basic Motivations for LSP Ping................................ 6
2.2. Motivations for LSP Ping for P2MP LSPs ....................... 8 2.2. Motivations for LSP Ping for P2MP LSPs........................ 6
2.3 Bootstrapping Other OAM Procedures Using LSP Ping ............. 9 2.3 Bootstrapping Other OAM Procedures Using LSP Ping.............. 8
3. Operation of LSP Ping for a P2MP LSP ........................... 9 3. Operation of LSP Ping for a P2MP LSP............................ 8
3.1. Identifying the LSP Under Test ............................... 9 3.1. Identifying the LSP Under Test................................ 9
3.1.1. Identifying a P2MP MPLS TE LSP ............................. 9 3.1.1. Identifying a P2MP MPLS TE LSP.............................. 9
3.1.1.1. RSVP P2MP IPv4 Session Sub-TLV ........................... 9 3.1.1.1. RSVP P2MP IPv4 Session Sub-TLV............................ 9
3.1.1.2. RSVP P2MP IPv6 Session Sub-TLV .......................... 10 3.1.1.2. RSVP P2MP IPv6 Session Sub-TLV............................ 9
3.1.2. Identifying a Multicast LDP LSP ........................... 10 3.1.2. Identifying a Multicast LDP LSP............................ 10
3.1.2.1. Multicast LDP FEC Stack Sub-TLV ......................... 11 3.1.2.1. Multicast LDP FEC Stack Sub-TLVs......................... 10
3.2. Ping Mode Operation ......................................... 12 3.1.2.2. Applicability to Multipoint-to-Multipoint LSPs........... 11
3.2.1. Controlling Responses to LSP Pings ........................ 12 3.2. Ping Mode Operation.......................................... 12
3.2.2. Ping Mode Egress Procedures ............................... 12 3.2.1. Controlling Responses to LSP Pings......................... 12
3.2.3. Jittered Responses ........................................ 13 3.2.2. Ping Mode Egress Procedures................................ 12
3.2.4. P2MP Responder Identifier TLV and Sub-TLVs ................ 14 3.2.3. Jittered Responses......................................... 12
3.2.5. Echo Jitter TLV ........................................... 15 3.2.4. P2MP Responder Identifier TLV and Sub-TLVs................. 13
3.2.6. Echo Response Reporting ................................... 15 3.2.4.1. Egress Address P2MP Responder Identifier Sub-TLVs........ 14
3.3. Traceroute Mode Operation ................................... 16 3.2.4.2. Node Address P2MP Responder Identifier Sub-TLVs.......... 14
3.3.1. Traceroute Responses at Non-Branch Nodes .................. 17 3.2.5. Echo Jitter TLV............................................ 15
3.3.1.1. Correlating Traceroute Responses ........................ 17 3.2.6. Echo Response Reporting.................................... 15
3.3.2. Traceroute Responses at Branch Nodes ..................... 18 3.2.6.1 Ping Responses at Transit and Branch Nodes................ 16
3.3.2.1. Node Properties TLV ..................................... 18 3.2.6.2 Ping Responses at Egress and Bud Nodes.................... 16
3.3.2.2. Branching Properties Sub-TLV ............................ 19 3.3. Traceroute Mode Operation.................................... 16
3.3.2.3. Egress Address Sub-TLV .................................. 20 3.3.1. Correlating Traceroute Responses........................... 17
3.3.2.4. Correlating Traceroute Responses ........................ 21 3.3.2. Traceroute Responses at Transit Nodes...................... 18
3.3.3. Traceroute Responses at Bud Nodes ......................... 21 3.3.3. Traceroute Responses at Branch Nodes....................... 18
3.3.4. Non-Response to Traceroute Echo Requests .................. 22 3.3.4. Traceroute Responses at Egress Nodes....................... 19
3.3.5. Additions to Downstream Mapping Multipath Information ..... 22 3.3.5. Traceroute Responses at Bud Nodes.......................... 19
3.3.6. Echo Response Reporting ................................... 24 3.3.6. Non-Response to Traceroute Echo Requests................... 20
3.3.6.1. Reporting Multiple Conditions Using The DDM TLV ......... 24 3.3.7 Use of Downstream Detailed Mapping TLV in Echo Request...... 20
4. Operation of LSP Ping for Bootstrapping Other OAM Mechanisms .. 25 4. Non-compliant Routers.......................................... 20
5. Non-compliant Routers ......................................... 26 5. OAM Considerations............................................. 20
6. OAM Considerations ............................................ 26 6. IANA Considerations............................................ 21
7. IANA Considerations ........................................... 27 6.1. New Sub-TLV Types............................................ 21
7.1. New Sub-TLV Types ........................................... 27 6.2. New TLVs..................................................... 21
7.2. New Multipath Type .......................................... 27 7. Security Considerations........................................ 22
7.3. New TLVs .................................................... 28 8. Acknowledgements............................................... 22
7.4. New Return Code ............................................. 28 9. References..................................................... 23
7.5. New Sub-TLV Value for the Downstream Detailed Mapping TLV ... 28 9.1 Normative References.......................................... 23
8. Security Considerations ....................................... 29 9.2 Informative References........................................ 23
9. Acknowledgements .............................................. 29 10. Authors' Addresses............................................ 24
10. Intellectual Property Considerations ......................... 29 11. Full Copyright Statement...................................... 25
11. Normative References ......................................... 30
12. Informative References ....................................... 30
13. Authors' Addresses ........................................... 31
14. Full Copyright Statement ..................................... 32
0. Change Log 0. Change Log
This section to be removed before publication as an RFC. This section to be removed before publication as an RFC.
0.1 Changes from 00 to 01 0.1 Changes from 00 to 01
- Update references. - Update references.
- Fix boilerplate. - Fix boilerplate.
skipping to change at page 4, line 44 skipping to change at page 4, line 33
Egress Address sub-TLVs. Egress Address sub-TLVs.
- Section 3.3.2.4: Clarify rules on presence of Multipath Information - Section 3.3.2.4: Clarify rules on presence of Multipath Information
in Downstream Mapping TLVs. in Downstream Mapping TLVs.
- Section 3.3.5: Clarify padding rules. - Section 3.3.5: Clarify padding rules.
- Section 3.3.6: Updated to use Downstream Detailed Mapping TLVs for - Section 3.3.6: Updated to use Downstream Detailed Mapping TLVs for
multiple return conditions reported by a single echo response. multiple return conditions reported by a single echo response.
- Section 7: Update IANA values and add new sub-sections. - Section 7: Update IANA values and add new sub-sections.
- Section 11: Add reference draft-ietf-mpls-lsp-ping-enhanced-dsmap. - Section 11: Add reference draft-ietf-mpls-lsp-ping-enhanced-dsmap.
- Section 13: Update Bill Fenner's coordinates. - Section 13: Update Bill Fenner's coordinates.
0.8 Changes from 07 to 08
- Removed the Node Properties TLV (Section 3.3.2.1 of version 07).
- Removed the New Multipath Type from Multipath Sub-TLV (Section
3.3.5 of version 07).
- Removed the Return Code Sub-TLV from Downstream Detailed TLV
(Section 3.3.6.1 of version 07), as it is already included in
draft-ietf-mpls-lsp-ping-enhanced-dsmap-02.
- Clarified the behavior of Responder Identifier TLV (Section
3.2.4 of version 07). Two new Sub-TLVs are introduced.
- Downstream Detailed Mapping TLV is now mandatory for implementing
P2MP OAM functionality.
- Split Multicast LDP TLV into two TLVs, one for P2MP and other for
MP2MP. Also added description to allow MP2MP ping by using this
draft.
- Removed Section 4. as it was a duplicate of Section 2.3.
1. Introduction 1. Introduction
Simple and efficient mechanisms that can be used to detect data plane Simple and efficient mechanisms that can be used to detect data plane
failures in point-to-point (P2P) Multiprotocol Label Switching (MPLS) failures in point-to-point (P2P) Multiprotocol Label Switching (MPLS)
Label Switched Paths (LSP) are described in [RFC4379]. The techniques Label Switched Paths (LSP) are described in [RFC4379]. The techniques
involve information carried in an MPLS "echo request" and "echo involve information carried in an MPLS "echo request" and "echo
reply", and mechanisms for transporting the echo reply. The echo reply", and mechanisms for transporting the echo reply. The echo
request and reply messages provide sufficient information to check request and reply messages provide sufficient information to check
correct operation of the data plane, as well as a mechanism to verify correct operation of the data plane, as well as a mechanism to verify
the data plane against the control plane, and thereby localize the data plane against the control plane, and thereby localize
skipping to change at page 11, line 14 skipping to change at page 10, line 46
message MUST carry a Target FEC Stack TLV, and this MUST carry message MUST carry a Target FEC Stack TLV, and this MUST carry
exactly one new sub-TLV: the Multicast LDP FEC Stack sub-TLV. This exactly one new sub-TLV: the Multicast LDP FEC Stack sub-TLV. This
sub-TLV uses fields from the multicast LDP messages [P2MP-LDP] and so sub-TLV uses fields from the multicast LDP messages [P2MP-LDP] and so
provides sufficient information to uniquely identify the LSP. provides sufficient information to uniquely identify the LSP.
The new sub-TLV is assigned a sub-type identifier as follows, and The new sub-TLV is assigned a sub-type identifier as follows, and
is described in the following section. is described in the following section.
Sub-Type # Length Value Field Sub-Type # Length Value Field
---------- ------ ----------- ---------- ------ -----------
TBD Variable Multicast LDP FEC Stack TBD Variable Multicast P2MP LDP FEC Stack
TBD Variable Multicast MP2MP LDP FEC Stack
3.1.2.1. Multicast LDP FEC Stack Sub-TLV 3.1.2.1. Multicast LDP FEC Stack Sub-TLVs
The format of the Multicast LDP FEC Stack sub-TLV is shown below. Both Multicast P2MP and MP2MP LDP FEC Stack have the same format, as
specified in the following figure.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Address Family | Address Length| Root LSR Addr | | Address Family | Address Length| Root LSR Addr |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
~ Root LSR Address (Cont.) ~ ~ Root LSR Address (Cont.) ~
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Opaque Length | Opaque Value ... | | Opaque Length | Opaque Value ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
~ ~ ~ ~
| | | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Address Family Address Family
A two octet quantity containing a value from ADDRESS FAMILY Two octet quantity containing a value from ADDRESS FAMILY NUMBERS
NUMBERS in [IANA-PORT] that encodes the address family for the in [IANA-PORT] that encodes the address family for the Root LSR
Root LSR Address. Address.
Address Length Address Length
The length of the Root LSR Address in octets. Length of the Root LSR Address in octets.
Root LSR Address Root LSR Address
An address of the LSR at the root of the P2MP LSP encoded Address of the LSR at the root of the P2MP LSP encoded according
according to the Address Family field. to the Address Family field.
Opaque Length Opaque Length
The length of the Opaque Value, in octets. The length of the Opaque Value, in octets.
Opaque Value Opaque Value
An opaque value elements of which uniquely identifies the P2MP LSP An opaque value element which uniquely identifies the P2MP LSP in
in the context of the Root LSR. the context of the Root LSR.
If the Address Family is IPv4, the Address Length MUST be 4. If the If the Address Family is IPv4, the Address Length MUST be 4. If the
Address Family is IPv6, the Address Length MUST be 16. No other Address Family is IPv6, the Address Length MUST be 16. No other
Address Family values are defined at present. Address Family values are defined at present.
3.1.2.2. Applicability to Multipoint-to-Multipoint LSPs
The mechanisms defined in this document can be extended to include
Multipoint-to-Multipoint (MP2MP) Multicast LSPs. In an MP2MP LSP
tree, any leaf node can be treated like a head node of a P2MP
tree. In other words, for MPLS OAM purposes, the MP2MP tree can be
treated like a collection of P2MP trees, with each MP2MP leaf node
acting like a P2MP head-end node. When a leaf node is acting like a
P2MP head-end node, the remaining leaf nodes act like egress nodes.
3.2. Ping Mode Operation 3.2. Ping Mode Operation
3.2.1. Controlling Responses to LSP Pings 3.2.1. Controlling Responses to LSP Pings
As described in Section 2.2, it may be desirable to restrict the As described in Section 2.2, it may be desirable to restrict the
operation of LSP Ping to a single egress. Since echo requests are operation of LSP Ping to a single egress. Since echo requests are
forwarded through the data plane without interception by the control forwarded through the data plane without interception by the control
plane (compare with traceroute mode), there is no facility to limit plane (compare with traceroute mode), there is no facility to limit
the propagation of echo requests, and they will automatically be the propagation of echo requests, and they will automatically be
forwarded to all (reachable) egresses. forwarded to all (reachable) egresses.
However, the intended egress under test can be identified by the However, the intended egress under test can be identified by the
inclusion of a P2MP Responder Identifier TLV containing an IPv4 P2MP inclusion of a P2MP Responder Identifier TLV. The details of this TLV
Responder Identifier sub-TLV or an IPv6 P2MP Responder Identifier and its Sub-TLVs are in section 3.2.4. The initiator may choose
sub-TLV. The P2MP Responder Identifier TLV SHOULD contain precisely whether only the node identified in the TLV responds or any node on
one sub-TLV. If the TLV contains no sub-TLVs it SHOULD be processed the path to the node identified in the TLV may respond.
as if the whole TLV were absent (causing all egresses to respond as
described below). If the TLV contains more than one sub-TLV, the
first MUST be processed as described in this document, and subsequent
sub-TLVs SHOULD be ignored.
An initiator may indicate that it wishes all egresses to respond to An initiator may indicate that it wishes all egresses to respond to
an echo request by omitting the P2MP Responder Identifier TLV. an echo request by omitting the P2MP Responder Identifier TLV.
Note that the ingress of a multicast LDP LSP will not know the Note that the ingress of a multicast LDP LSP will not know the
identities of the egresses of the LSP except by some external means identities of the egresses of the LSP except by some external means
such as running P2MP LSP Ping to all egresses. such as running P2MP LSP Ping to all egresses.
3.2.2. Ping Mode Egress Procedures 3.2.2. Ping Mode Egress Procedures
An egress node is RECOMMENDED to rate limit its receipt of echo An egress node is RECOMMENDED to rate limit its receipt of echo
request messages as described in [RFC4379]. After rate limiting, an request messages as described in [RFC4379]. After rate limiting, an
egress node that receives an echo request carrying an RSVP P2MP IPv4 egress node that receives an echo request carrying an RSVP P2MP IPv4
Session sub-TLV, an RSVP P2MP IPv6 Session sub-TLV, or a Multicast Session sub-TLV, an RSVP P2MP IPv6 Session sub-TLV, or a Multicast
LDP FEC Stack sub-TLV MUST determine whether it is an intended egress LDP FEC Stack sub-TLV MUST determine whether it is an egress of the
of the P2MP LSP in question by checking with the control plane. If it P2MP LSP in question by checking with the control plane.
is not supposed to be an egress, it MUST respond according to the
setting of the Response Type field in the echo message following the
rules defined in [RFC4379].
If the egress node that receives an echo request and allows it - If the node is not an egress, it MUST respond according to the
through its rate limiting is an intended egress of the P2MP LSP, the setting of the Response Type field in the echo message following
node MUST check to see whether it is an intended Ping recipient. If a the rules defined in [RFC4379].
P2MP Responder Identifier TLV is present and contains an address that
indicates any address that is local to the node, the node MUST
respond according to the setting of the Response Type field in the
echo message following the rules defined in [RFC4379]. If the P2MP
Responder Identifier TLV is present, but does not identify the egress
node, it MUST NOT respond to the echo request. If the P2MP Responder
Identifier TLV is not present (or, in the error case, is present, but
does not contain any sub-TLVs), but the egress node that received the
echo request is an intended egress of the LSP, the node MUST respond
according to the setting of the Response Type field in the echo
message following the rules defined in [RFC4379].
3.2.3. Jittered Responses - If the node is an egress of the P2MP LSP, the node must
check whether it is a receipient of the echo request.
- If a P2MP Responder Identifier TLV is present, then the node
must follow the procedures defined in section 3.2.4 to determine
whether it should respond to the reqeust or not.
- If the P2MP Responder Identifier TLV is not present (or, in the
error case, is present, but does not contain any sub-TLVs), and
the egress node that received the echo request is an intended
egress of the LSP, the node MUST respond according to the setting
of the Response Type field in the echo message following the
rules defined in [RFC4379].
3.2.3. Jittered Responses
The initiator (ingress) of a ping request MAY request the responding The initiator (ingress) of a ping request MAY request the responding
egress to introduce a random delay (or jitter) before sending the egress to introduce a random delay (or jitter) before sending the
response. The randomness of the delay allows the responses from response. The randomness of the delay allows the responses from
multiple egresses to be spread over a time period. Thus this multiple egresses to be spread over a time period. Thus this
technique is particularly relevant when the entire LSP tree is being technique is particularly relevant when the entire LSP tree is being
pinged since it helps prevent the ingress (or nearby routers) from pinged since it helps prevent the ingress (or nearby routers) from
being swamped by responses, or from discarding responses due to rate being swamped by responses, or from discarding responses due to rate
limits that have been applied. limits that have been applied.
It is desirable for the ingress to be able to control the bounds It is desirable for the ingress to be able to control the bounds
within which the egress delays the response. If the tree size is within which the egress delays the response. If the tree size is
small, only a small amount of jitter is required, but if the tree is small, only a small amount of jitter is required, but if the tree is
large, greater jitter is needed. The ingress informs the egresses of large, greater jitter is needed. The ingress informs the egresses of
the jitter bound by supplying a value in a new TLV (the Echo Jitter the jitter bound by supplying a value in a new TLV (the Echo Jitter
TLV) carried on the echo request message. If this TLV is present, TLV) carried on the echo request message. If this TLV is present, the
the responding egress MUST delay sending a response for a random responding egress MUST delay sending a response for a random amount
amount of time between zero seconds and the value indicated in the of time between zero milliseconds and the value indicated in the
TLV. If the TLV is absent, the responding egress SHOULD NOT introduce TLV. If the TLV is absent, the responding egress SHOULD NOT introduce
any additional delay in responding to the echo request. any additional delay in responding to the echo request.
LSP ping SHOULD NOT be used to attempt to measure the round-trip LSP ping SHOULD NOT be used to attempt to measure the round-trip
time for data delivery. This is because the LSPs are unidirectional, time for data delivery. This is because the LSPs are unidirectional,
and the echo response is often sent back through the control plane. and the echo response is often sent back through the control plane.
The timestamp fields in the echo request/response MAY be used to The timestamp fields in the echo request/response MAY be used to
deduce some information about delivery times and particularly the deduce some information about delivery times and particularly the
variance in delivery times. variance in delivery times.
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If no sub-TLVs are present, the TLV MUST be processed as if it If no sub-TLVs are present, the TLV MUST be processed as if it
were absent. If more than one sub-TLV is present the first MUST were absent. If more than one sub-TLV is present the first MUST
be processed as described in this document, and subsequent be processed as described in this document, and subsequent
sub-TLVs SHOULD be ignored. sub-TLVs SHOULD be ignored.
The P2MP Responder Identifier TLV only has meaning on an echo request The P2MP Responder Identifier TLV only has meaning on an echo request
message. If present on an echo response message, it SHOULD be message. If present on an echo response message, it SHOULD be
ignored. ignored.
Two sub-TLVs are defined for inclusion in the P2MP Responder Four sub-TLVs are defined for inclusion in the P2MP Responder
Identifier TLV carried on the echo request message. These are: Identifier TLV carried on the echo request message. These are:
Sub-Type # Length Value Field Sub-Type # Length Value Field
---------- ------ ----------- ---------- ------ -----------
1 4 IPv4 P2MP Responder Identifier 1 4 IPv4 Egress Address P2MP Responder Identifier
2 16 IPv6 P2MP Responder Identifier 2 16 IPv6 Egress Address P2MP Responder Identifier
3 4 IPv4 Node Address P2MP Responder Identifier
4 16 IPv6 Node Address P2MP Responder Identifier
The value of an IPv4 P2MP Responder Identifier consists of four The content of these Sub-TLVs are defined in the following
octets of an IPv4 address. The IPv4 address is in network byte order. sections. Also defined is the intended behavior of the responding
node upon receiving any of these Sub-TLVs. Please note that the echo
response is always controlled by Response Type field in the echo
message as defined in [RFC4379] and whether or not the responding
node is part for the P2MP tree being identified in the Target FEC
Stack TLV. The Sub-TLVs defined in this section provide additional
constraints to those requirements and are not a replacement for those
requirements.
The value of an IPv6 P2MP Responder Identifier consists of sixteen 3.2.4.1. Egress Address P2MP Responder Identifier Sub-TLVs
octets of an IPv6 address. The IPv6 address is in network byte order.
The IPv4 or IPv6 Egress Address P2MP Responder Identifier Sub-TLVs
MAY be used in an echo request carrying RSVP P2MP Session
Sub-TLV. They SHOULD NOT be used with an echo request carrying
Multicast LDP FEC Stack Sub-TLV.
A node that receives an echo request with this Sub-TLV present MUST
respond only if the node lies on the path to the address in the
Sub-TLV.
The address in this Sub-TLV SHOULD be of an egress or bud node and
SHOULD NOT be of a transit or branch node. This address MUST be known
to the nodes upstream of the target node, possibly via control plane
signaling, such as RSVP. This Sub-TLV may be used to trace a specific
egress or bud node in the P2MP tree.
3.2.4.2. Node Address P2MP Responder Identifier Sub-TLVs
The IPv4 or IPv6 Node Address P2MP Responder Identifier Sub-TLVs MAY
be used in an echo request carrying either RSVP P2MP Session or
Multicast LDP FEC Stack Sub-TLV.
A node that receives an echo request with this Sub-TLV present MUST
respond only if the address in the Sub-TLV corresponds to any address
that is local to the node. This address in the Sub-TLV may be of any
physical interface or may be the router id of the node itself.
The address in this Sub-TLV SHOULD be of any transit, branch, bud or
egress node for that P2MP tree. This Sub-TLV may be used to ping any
specific node in the P2MP tree.
3.2.5. Echo Jitter TLV 3.2.5. Echo Jitter TLV
A new TLV is defined for inclusion in the Echo request message. A new TLV is defined for inclusion in the Echo request message.
The Echo Jitter TLV is assigned the TLV type value TBD and is encoded The Echo Jitter TLV is assigned the TLV type value TBD and is encoded
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
skipping to change at page 15, line 25 skipping to change at page 15, line 37
| Type = TBD (Jitter TLV) | Length = 4 | | Type = TBD (Jitter TLV) | Length = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Jitter time | | Jitter time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Jitter time: Jitter time:
This field specifies the upper bound of the jitter period that This field specifies the upper bound of the jitter period that
should be applied by a responding node to determine how long to should be applied by a responding node to determine how long to
wait before sending an echo response. A responding node SHOULD wait before sending an echo response. A responding node SHOULD
wait a random amount of time between zero seconds and the value wait a random amount of time between zero milliseconds and the
specified in this field. value specified in this field.
Jitter time is specified in milliseconds. Jitter time is specified in milliseconds.
The Echo Jitter TLV only has meaning on an echo request message. If The Echo Jitter TLV only has meaning on an echo request message. If
present on an echo response message, it SHOULD be ignored. present on an echo response message, it SHOULD be ignored.
3.2.6. Echo Response Reporting 3.2.6. Echo Response Reporting
Echo response messages carry return codes and subcodes to indicate Echo response messages carry return codes and subcodes to indicate
the result of the LSP Ping (when the ping mode is being used) as the result of the LSP Ping (when the ping mode is being used) as
described in [RFC4379]. described in [RFC4379].
When the responding node reports that it is an egress, it is clear When the responding node reports that it is an egress, it is clear
that the echo response applies only to the reporting node. Similarly, that the echo response applies only to the reporting node. Similarly,
when a node reports that it does not form part of the LSP described when a node reports that it does not form part of the LSP described
by the FEC (i.e. their is a misconnection) then the echo response by the FEC (i.e. there is a misconnection) then the echo response
applies to the reporting node. applies to the reporting node.
However, it should be noted that an echo response message that However, it should be noted that an echo response message that
reports an error from a transit node may apply to multiple egress reports an error from a transit node may apply to multiple egress
nodes (i.e. leaves) downstream of the reporting node. In the case of nodes (i.e. leaves) downstream of the reporting node. In the case of
the Ping mode of operation, it is not possible to correlate the the Ping mode of operation, it is not possible to correlate the
reporting node to the affected egresses unless the shape of the P2MP reporting node to the affected egresses unless the shape of the P2MP
tree is already known, and it may be necessary to use the Traceroute tree is already known, and it may be necessary to use the Traceroute
mode of operation (see Section 3.3) to further diagnose the LSP. mode of operation (see Section 3.3) to further diagnose the LSP.
Note also that a transit node may discover an error but also Note also that a transit node may discover an error but also
determine that while it does lie on the path of the LSP under test, determine that while it does lie on the path of the LSP under test,
it does not lie on the path to the specific egress being tested. In it does not lie on the path to the specific egress being tested. In
this case, the node SHOULD NOT generate an echo response. this case, the node SHOULD NOT generate an echo response.
A reporting node that is a branch node may need to report multiple 3.2.6.1 Ping Responses at Transit and Branch Nodes
different errors (for different downstream branches). This is
discussed further in Section 3.3.6. If the TTL of the MPLS packet carrying an echo request expires at a
transit or branch node, the packet MUST be passed to the control
plane as specified in [RFC4379].
If the P2MP Responder Identifier is not present or does not contain
any Sub-TLV, then the node MUST respond. If the P2MP Responder
Identifier Sub-TLV is present, then the node MUST respond as per
section 3.2.4.
If the echo response being sent is not indicating an error condition,
such as Malformed request, then the Return Code in the echo response
header may be set to value 8 ('Label switched at stack-depth <RSC>')
or any other error value as needed.
3.2.6.2 Ping Responses at Egress and Bud Nodes
The echo request packet MUST be sent to the control plane at egress
and bud nodes.
If the P2MP Responder Identifier is not present or does not contain
any Sub-TLV, then the node MUST respond. If the P2MP Responder
Identifier Sub-TLV is present, then the node MUST respond as per
section 3.2.4.
If the echo response being sent is not indicating an error condition,
such as Malformed request, then the Return Code in the echo response
header may be set to value 3 ('Replying router is an egress for the
FEC at stack-depth <RSC>') or any other error value as needed.
3.3. Traceroute Mode Operation 3.3. Traceroute Mode Operation
The traceroute mode of operation is described in [RFC4379]. Like The traceroute mode of operation is described in [RFC4379]. Like
other traceroute operations, it relies on the expiration of the TTL other traceroute operations, it relies on the expiration of the TTL
of the packet that carries the echo request. Echo requests may of the packet that carries the echo request. When the TTL expires the
include a Downstream Mapping TLV, and when the TTL expires the echo echo request is passed to the control plane on the transit node which
request is passed to the control plane on the transit node which responds according to the Response Type in the message (and any
responds according to the Response Type in the message. A responding Responder Identifier TLV that may be present).
node fills in the fields of the Downstream Mapping TLV to indicate
the downstream interfaces and labels used by the reported LSP from Echo requests MAY include a Downstream Detailed Mapping TLV, and a
the responding node. In this way, by successively sending out echo responding node fills in the fields of the Downstream Detailed
requests with increasing TTLs, the ingress may gain a picture of the Mapping TLV to indicate the downstream interfaces and labels used by
path and resources used by an LSP up to the point of failure when no the reported LSP from the responding node. In this way, by
successively sending out echo requests with increasing TTLs, the
ingress may gain a picture of the path and resources used by an
LSP. This process continues either to the point of failure when no
response is received, or an error response is generated by a node response is received, or an error response is generated by a node
where the control plane does not expect to be handling the LSP. where the control plane does not expect to be handling the LSP.
This mode of operation is equally applicable to P2MP MPLS TE LSPs For P2MP Traceroute, a node MUST support Downstream Detailed Mapping
as described in the following sections. TLV [DDMT]. Downstream Mapping TLV [RFC4379] SHOULD NOT be used for
P2MP traceroute functionality. As per Section 4.3 of [DDMT],
Downstream Mapping TLV is being deprecated. A node MUST ignore any
Downstream Mapping TLV it receives in the echo request.
If there are nodes in the P2MP tree that do not support Downstream
Detailed Mapping TLV, they will send an echo reply with Return Code
set to 2. The ingress node upon receiving such a value SHOULD send
subsequent echo requests with a larger TTL.
The traceroute mode of operation is equally applicable to P2MP MPLS
TE LSP and P2MP Multicast LDP LSP and is described in the following
sections.
The traceroute mode can be applied to all destinations of the P2MP The traceroute mode can be applied to all destinations of the P2MP
tree just as in the ping mode. In the case of P2MP MPLS TE LSPs, the tree just as in the ping mode. In the case of P2MP MPLS TE LSPs, the
traceroute mode can also be applied to individual traceroute targets traceroute mode can also be applied to individual traceroute targets
identified by the presence of a P2MP Responder Identifier TLV. These identified by the presence of a P2MP Responder Identifier TLV. In
targets may be egresses or transit nodes. However, since a transit this case, the responding node must follow the behavior specified in
node of a multicast LDP LSP is unable to determine whether it lies on 3.2.4. These targets SHOULD be egresses or bud nodes. However, since
the path to any one destination or any other transit node, the a transit node of a multicast LDP LSP is unable to determine whether
traceroute mode limited to specific nodes of such an LSP MUST NOT be it lies on the path to any one destination or any other transit node,
used. the traceroute mode limited to specific nodes of such an LSP MUST NOT
be used.
Note that the addresses specified in the P2MP Responder Identifier
TLV need not be egresses: they could be transit nodes on the LSP. The
processing rules here and in the following sections apply equally to
egress and transit nodes.
In the absence of a P2MP Responder Identifier TLV, the echo request In the absence of a P2MP Responder Identifier TLV, the echo request
is asking for traceroute information applicable to all egresses. is asking for traceroute information applicable to all egresses.
The echo response jitter technique described for the ping mode is The echo response jitter technique described for the ping mode is
equally applicable to the traceroute mode and is not additionally equally applicable to the traceroute mode and is not additionally
described in the procedures below. described in the procedures below.
3.3.1. Traceroute Responses at Non-Branch Nodes 3.3.1. Correlating Traceroute Responses
When the TTL for the MPLS packet carrying an echo request expires the
packet MUST be passed to the control plane as specified in [RFC4379].
If the LSP under test is a multicast LDP LSP and if the echo request
carries a P2MP Responder Identifier TLV the node MUST treat the echo
request as malformed and MUST process it according to the rules
specified in [RFC4379].
Otherwise, the node MUST NOT return an echo response unless the
responding node lies on the path of the P2MP LSP to the node (egress
or transit) identified by the P2MP Responder Identifier TLV carried
on the request, or if no such sub-TLV is present.
If sent, the echo response MUST identify the next hop of the path of
the LSP in the data plane by including a Downstream Mapping TLV as
described in [RFC4379].
3.3.1.1. Correlating Traceroute Responses
When traceroute is being simultaneously applied to multiple
responders (e.g., egresses), it is important that the ingress should
be able to correlate the echo responses with the branches in the P2MP
tree. Without this information the ingress will be unable to
determine the correct ordering of transit nodes. One possibility is
for the ingress to poll the path to each responder in turn, but this
may be inefficient, undesirable, or (in the case of multicast LDP
LSPs) illegal.
The Downstream Mapping TLV that MUST be included in the echo response
indicates the next hop from each responding node, and this
information supplied by a non-branch node can be pieced together by
the ingress to reconstruct the P2MP tree although it may be necessary
to refer to the routing information distributed by the IGP to
correlate next hop addresses and node reporting addresses in
subsequent echo responses.
In order to facilitate more easy correlation of echo responses, the
Downstream Mapping TLV can also contain Multipath Information as
described in [RFC4379] to identify to which responders (transit
nodes or egresses) the echo response applies. This information:
- Cannot be present when the information is not known by the
responding node. For example, for a multicast LDP LSP, the branch
node will not know through normal LDP signaling which leaf nodes
lie on which downstream branch.
- SHOULD be present when the information is known by the responding
node. That is for P2MP MPLS TE LSPs when the echo request applies
to all egresses or to a specific single transit node or egress.
The format of the information in the Downstream Mapping TLV for
P2MP MPLS LSPs is described in section 3.3.5.
3.3.2. Traceroute Responses at Branch Nodes
A branch node may need to identify more than one downstream interface
in a traceroute echo response if some of the nodes identified in the
P2MP Responder Identifier TLV that are being traced lie on different
branches. This will always be the case for any branch node if all
egresses are being traced.
[RFC4379] describes how multiple Downstream Mapping TLVs should be
included in an echo response, each identifying exactly one downstream
interface that is applicable to the LSP.
A branch node MUST follow the procedures described in Section 3.3.1
to determine whether it should respond to an echo request. The branch
node MUST add a Downstream Mapping TLV (or Downstream Detailed
Mapping TLV - see Section 3.3.7) to the echo response for each
outgoing branch that it reports, but it MUST NOT report branches that
do not lie on the path to one of the destinations being traced. Thus
a branch node may sometimes only need to respond with a single
Downstream Mapping TLV; for example, consider the case where the
traceroute is directed to only a single egress node. Therefore,
the presence of only one Downstream Mapping TLV in an echo response
does not guarantee that the reporting node is not a branch node.
To report on its branching properties on a particular LSP, the
responding node MAY include an optional TLV called the Node
Properties TLV. This new TLV (see Section 3.3.2.1) can carry sub-
TLVs, one of which (the Branching Properties sub-TLV - see Section
3.3.2.2) allows the reporting node to describe the branching
characteristics of the LSP at the reporting node.
3.3.2.1. Node Properties TLV
A new TLV has been added to the set of optional TLVs that may be
carried on an echo response message.
Type # Value Field
------ ------------
TBD Node properties
The Node Properties TLV MAY be included in an echo response message.
If more than one such TLV is present, the first MUST be processed and
subsequent instances SHOULD be ignored.
The Node Properties TLV is used to report characteristics of the
reporting node, and the LSP at that node. This distinguishes it from
the Downstream Mapping TLV [RFC4379] and the Downstream Detailed
Mapping TLV [DDMT] used to report characteristics of specific out-
segments an LSP.
The Node Properties TLV is a standard LSP Ping TLV as defined in
[RFC4379]. It has the following format.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: :
: First Sub-TLV :
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
~ Further Sub-TLVs ~
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The content of the Node Properties TLV is a series of one or more
sub-TLVs. The Nore Properties TLV SHOULD contain one or more sub-TLVs
and MUST be ignored if there are no sub-TLVs present.
Each sub-TLV consists of the following fields as per [RFC4379]:
- Two octet Type field: A value indicating the sub-TLV type.
- Two octet Length field: A value indicating the total length of the
Value field.
- A Value field carrying the data of the sub-TLV. The content of the
Value field is padded to a four byte boundary with zero-filled
octets so that the Length field is always a multiple of 4.
3.3.2.2. Branching Properties Sub-TLV
This document defines the Branching Properties sub-TLV carried in the
Node Properties TLV. The Branching Properties sub-TLV is optional. If
more than one such sub-TLV is found in a Node Properties TLV, the
first MUST be processed and subsequent instances SHOULD be ignored.
The sub-TLV may be used for P2MP and P2P LSPs.
The Branching Properties sub-TLV is formed as described in Section
3.3.2.1. The Value field has the following format.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Downstream Branch Count | Egress Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Downstream Branch Count
This field reports the number of downstream branches from the
reporting node for this LSP. The number may be zero for an egress,
one for a non-branch node, and more than one for a branch node.
Note that the value reported here may be greater than the number
of Downstream Mapping TLVs present in the echo response message
since those TLVs only report on the specific egresses queried. This
value may be of use in detecting faults caused by delay introduced
by the data replication mechanism at branch nodes.
Egress Count
This field reports the number of egresses local to the reporting
node. Thus, for non-zero values the reporting node is either a leaf
or a bud. When the value reported is non-zero, the reporting node
MAY also include an Egress Address Sub-TLV for each local egress
(see Section 3.3.2.3).
For example, a branch node that has two downstream next hops on the
LSP and that also delivers payload data to one local egress would set
the two fields to 2 and 1 respectively.
3.3.2.3. Egress Address Sub-TLV
This document defines the IPv4 and IPv6 Egress Address sub-TLVs
carried in the Node Properties TLV. These TLVs are optional, and more
than one instance of the sub-TLVs may legitimately be present.
The Egress Address sub-TLVs are formed as described in Section
3.3.2.1. The Value field has the following formats.
IPv4 Egress Address Sub-TLV
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Egress Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv6 Egress Address Sub-TLV
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Egress Address |
| (16 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Egress Address sub-TLVs are optional. They MAY be included in a
Node Properties TLV when reporting node is an egress (leaf or bud)
for the LSP being tested. The sub-TLV may be used for P2MP and P2P
LSPs.
When one or more Egress Address sub-TLVs are present and the Branch
Properties sub-TLV is also present, the value of the Egress Count
field in the Branch Properties sub-TLV SHOULD be the same as the
number of Egress Address sub-TLVs.
The address contained in an Egress Address sub-TLV is the egress
address to which the data is delivered. If there is just one egress
and if the egress address is the same as the local node address
carried in the main echo response message, both the Branching
Properties sub-TLV and the Egress Address sub-TLV MAY be omitted as
in legacy LSP Ping implementations.
3.3.2.4. Correlating Traceroute Responses
Just as with non-branches, it is important that the echo responses
from branch nodes provide correlation information that will allow the
ingress to work out to which branch of the LSP the response applies.
The P2MP tree can be determined by the ingress using the identity of
the reporting node and the next hop information from the previous
echo response, just as with echo responses from non-branch nodes.
As with non-branch nodes, in order to facilitate more easy
correlation of echo responses, the Downstream Mapping TLV can also
contain Multipath Information as described in [RFC4379] to identify
to which nodes the echo response applies. This information:
- Cannot be present when the information is not known by the
responding node. For example, for a multicast LDP LSP, the branch
node will not know through normal LDP signaling which leaf nodes
lie on which downstream branch.
- SHOULD be present when the information is known by the responding
node. That is for P2MP MPLS TE LSPs when the echo request applies
to all egresses or to a specific single transit node or egress.
The format of the information in the Downstream Mapping TLV for
P2MP MPLS LSPs is described in section 3.3.5.
3.3.3. Traceroute Responses at Bud Nodes
Some nodes on a P2MP MPLS LSP may be egresses, but also have
downstream node. Such nodes are known as bud nodes [RFC4461].
A bud node MUST respond to a traceroute echo request just as a branch
node would, but it MUST also indicate to the ingress that it is an
egress in its own right. The issue to be resolved here is how to
indicate that the reporting node is an egress when it is also
providing one or more Downstream Mapping TLVs that indicate that it
has downstream neighbors.
This is achieved by the inclusion of a Node Properties TLV with a
Branch Properties sub-TLV indicating the number of local egresses and
the number of downstream branches. The bud node MAY also include one
or more Egress Address sub-TLVs in the Node Properties TLV to report
on the local egresses.
3.3.4. Non-Response to Traceroute Echo Requests
The nature of P2MP MPLS TE LSPs in the data plane means that
traceroute echo requests may be delivered to the control plane of
nodes that must not reply to the request because, although they lie
on the P2MP tree, they do not lie on the path to the node that is
being traced.
Thus, a node on a P2MP MPLS LSP MUST NOT respond to an echo request
when the TTL has expired if any of the following applies:
- The Reply Type indicates that no reply is required [RFC4379] When traceroute is simultaneously applied to multiple responders
(e.g. egresses), it is important that the ingress is able to
correlate the echo responses with the nodes in the P2MP tree. Without
this information the ingress will be unable to determine the correct
ordering of transit nodes. One possibility is for the ingress to poll
the path to each responder in turn, but this may be inefficient,
undesirable, or (in the case of multicast LDP LSPs) illegal.
- There is a P2MP Responder Identifier TLV present on the echo The Downstream Detailed Mapping TLV MUST be included in the echo
request (which means that the LSP is a P2MP MPLS TE LSP), but the response from transit, bud, or branch nodes. The information from
address does not identify a node that is reached through this node Downstream Detailed Mapping TLV can be pieced together by the ingress
for this particular P2MP MPLS LSP. to reconstruct the P2MP tree although it may be necessary to refer to
the routing information distributed by the IGP to correlate next hop
addresses and node reporting addresses in subsequent echo responses.
Note that when no response to an echo request is received by the The following sections describe the Return Code used in the echo
ingress (perhaps because the transit node has failed, or perhaps response header and in the Downstream Detailed Mapping TLV. It is
because the transit node does not support LSP Ping), then as per possible to identify the type of node (transit, branch, bud and
[RFC4379] the subsequent echo request (with a larger TTL) SHOULD be egress) by using various values in the Return Code and presence of
sent with Downstream Mapping TLV "Downstream IP Address" field set to Downstream Detailed Mapping TLV.
the ALLROUTERs multicast address until a reply is received with a
Downstream Mapping TLV.
3.3.5. Additions to Downstream Mapping Multipath Information 3.3.2. Traceroute Responses at Transit Nodes
A new value for the Multipath Type is defined to indicate that the When the TTL of the MPLS packet carrying an echo request expires the
reported Multipath Information applies to a P2MP MPLS TE LSP and may packet MUST be passed to the control plane as specified in [RFC4379].
contain a list of node identifiers that indicate the egress nodes and
(in the case where the P2MP Responder Identifier TLV was used on the
echo request to identify non-egress nodes) transit nodes that can be
reached through the reported interface. This Multipath Type MUST NOT
be used for a multicast LDP LSP.
Type # Address Type Multipath Information If the echo request packet contains an IPv4 or IPv6 Egress Address
--- ---------------- ------------------------------ P2MP Responder Identifier TLV, and the FEC is IPv4 or IPv6 P2MP TE
TBD P2MP responders List of reachable P2MP nodes LSP, then the node MUST respond only if the node lies on the path to
the egress specified in the Sub-TLV.
Note that a list of nodes may include IPv4 and IPv6 identifiers since If the LSP under test is a multicast LDP LSP and echo request has an
these may be mixed in the P2MP MPLS TE LSP. IPv4 or IPv6 Egress Address P2MP Responder Identifier TLV, then the
node MUST treat the echo request as malformed and MUST process it
according to the rules specified in [RFC4379].
The Multipath Length field continues to identify the length of the If the echo response being sent is not indicating an error condition,
Multipath Information just as in [RFC4379] (that is, not including such as Malformed request, it MUST identify the next hop of the path
the downstream labels), and the downstream label (or potential stack of the LSP in the data plane by including a Downstream Detailed
thereof) is also handled just as in [RFC4379]. The format of the Mapping TLV as described in [DDMT].
Multipath Information for a Multipath Type of P2MP responders is as
follows.
0 1 2 3 The Return Code in echo response header will be value TBD ('See DDM
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 TLV for Return Code and Return SubCode') as defined in [DDMT]. The
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Return Code for the Downstream Detailed Mapping TLV will depend on
| Address Type | Responder Address (4 or 16 octets) | the state of the output interface.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| (continued) | :
+-+-+-+-+-+-+-+-+ :
: Further Address Types and Responder Addresses :
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Address Type 3.3.3. Traceroute Responses at Branch Nodes
This field indicates whether the address that follows is an IPv4 A branch node MUST follow the procedures described in Section 3.3.2
or IPv6 address, and so implicitly encodes the length of the to determine whether it should respond to an echo request.
address.
Two values are defined and mirror the values used in the Address If the P2MP Responder Identifier is not present or does not contain
Type field of the Downstream Mapping TLV itself. any Sub-TLV (that is, if all egresses are being traced), then the
branch node MUST add a Downstream Detailed Mapping TLV to the echo
response for each outgoing branch that it reports.
Type # Address Type If an IPv4 or IPv6 Egress Address P2MP Responder Identifier is
------ ------------ present, it MUST report only the branch that is on the path to the
1 IPv4 specified egress node and it MUST NOT report the other branches.
3 IPv6
Responder Address The Return Code in echo response header will be value TBD ('See DDM
TLV for Return Code and Return SubCode') as defined in [DDMT]. The
Return Code for each of the Downstream Detailed Mapping TLV will
depend on the state of the output interface being reported in this
TLV.
An egress or transit node of this P2MP MPLS TE LSP that is 3.3.4. Traceroute Responses at Egress Nodes
reached through the interface indicated by the Downstream
Mapping TLV and for which the traceroute echo request was
enquiring.
Note that padding to ensure that the whole Multipath information is If P2MP Responder Identifier is not present or does not contain any
aligned to a four-octet boundary is applied only after the last Sub-TLV (that is, if all egresses are being traced), then the egress
responder address in the list. That is, each successive Address Type node MUST respond to the echo request.
follows on immediately after the previous Responder Address.
3.3.6. Echo Response Reporting If an IPv4 or IPv6 Egress Address P2MP Responder Identifier is
present, it MUST respond only if the specified address belongs the
egress node.
Echo responses are generated in response to traceroute echo requests Egress node MUST NOT return a Downstream Detailed Mapping TLV.
at transit, branch, and bud nodes as described in Sections 3.3.1,
3.3.2, and 3.3.3, while egress responses are as described in The Return Code in the echo response header will be value 3 ('Replying
router is an egress for the FEC at stack-depth <RSC>') as defined in
[RFC4379]. [RFC4379].
Note, however, that a branch or bud node may have multiple downstream 3.3.5. Traceroute Responses at Bud Nodes
branches, and a transit node may have multiple downstream egresses
(reached on the same branch). It may be the case that different
conditions need to be reported for different branches or egresses.
The echo response message defined in [RFC4379] has space for only a
single return code and subcode pair, so where more than one return
condition is reported by a single node it acts as follows.
- It SHOULD use the Downstream Detailed Mapping TLV [DDMT] in place
of the Downstream Mapping TLV, and encode the return code as
described in Section 3.3.6.1.
- It MAY report each condition in a separate echo response in which
case MUST limit the downstream mapping information on each echo
response to those branches/egresses to which the response applies.
The use of multiple echo response messages to report errors might
cause issues for an initiator that does not know how many responses
it should wait for. For that reason, multiple messages should be
used with care.
3.3.6.1. Reporting Multiple Conditions Using The DDM TLV
When multiple different return codes are indicated on a single echo
response message they MUST be carried in separate instances on the
Downstream Detailed Mapping (DDM) TLV [DDMT]. That is, each instance
of a DDM TLV carries one return code, and all information carried in
that TLV MUST be limited to branches/egresses to which that return
code applies. However, more than one DDM TLV on the same echo
response MAY carry the same return code.
The echo response message still carries a Return Code and a Return
Subcode field. In order to clearly indicate that the relevant return
codes are carried in the DDM TLV, a new return code is defined to be
carried in the Return Code field of the echo response message as
follows:
Value Meaning
----- -------
TBD See DDM TLV for more details
The Return Subcode for this Return Code MUST be set to zero and
MUST be ignored.
The DDM TLV is defined as carrying a set of sub-TLVs. A new sub-TLV,
the Return Code sub-TLV, is defined here to carry a return code and
return subcode.
0 1 2 3 Some nodes on a P2MP MPLS LSP may be an egress as well as a branch
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 (i.e. have one or more downstream nodes). Such nodes are known as bud
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ nodes [RFC4461]. A bud node's response is a combination of branch
| Return Code | Return Subcode| Reserved | node and egress node behavior.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The length of the Return Code sub-TLV is 8. If P2MP Responder Identifier is not present or does not contain any
Sub-TLV (that is, if all egresses are being traced), then the bud
node MUST respond to the echo request. It MUST add a Downstream
Detailed Mapping TLV to the echo response for each outgoing branch
that it reports. The Return Code in the echo response header will be
value 3 ('Replying router is an egress for the FEC at stack-depth
<RSC>') as defined in [RFC4379]. The Return Code for each of the
Downstream Detailed Mapping TLV will depend on the state of the
output interface being reported in this TLV.
Return Code If an IPv4 or IPv6 Egress Address P2MP Responder Identifier is
As defined for inclusion in the echo response message in [RFC4379]. present, and the specified address belongs the bud node, then it MUST
respond as if it were an egress node. The Return Code in the echo
response header will be value 3 ('Replying router is an egress for
the FEC at stack-depth <RSC>') as defined in [RFC4379]. It MUST NOT
report any Downstream Detailed Mapping TLV.
Return Subcode If an IPv4 or IPv6 Egress Address P2MP Responder Identifier is
As defined for inclusion in the echo response message in [RFC4379]. present, and the bud node lies on the path to the specified egress
address, then it MUST respond as if it was a branch node. The Return
Code in the echo response header will be value TBD ('See DDM TLV for
Return Code and Return SubCode') as defined in [DDMT]. The Return
Code for each of the Downstream Detailed Mapping TLV will depend on
the state of the output interface being reported in this TLV.
Reserved 3.3.6. Non-Response to Traceroute Echo Requests
SHOULD be set to zero on transmission and MUST be ignored on
receipt.
If the Return Code of the echo response message is not set to "See There are multiple reasons for which an ingress node may not receive
DDM TLV for more details" then any Return Code sub-TLV present in a a response to its echo request. For example, perhaps because the
DDM TLV SHOULD be ignored. transit node has failed, or perhaps because the transit node does not
support LSP Ping, or the Responder Identifier TLV failed to match a
valid node.
If the Return Code of the echo response message is set to "See DDM When no response to an echo request is received by the ingress, then
TLV for more details" then a Return Code sub-TLV MUST be present in as per [RFC4379] the subsequent echo request with a larger TTL SHOULD
each DDM TLV. Subsequent Return Code sub-TLVs present in the same DDM be sent.
TLV SHOULD be ignored.
4. Operation of LSP Ping for Bootstrapping Other OAM Mechanisms 3.3.7 Use of Downstream Detailed Mapping TLV in Echo Request
Bootstrapping of other OAM procedures can be achieved using the If no Responder Identifier TLV is being used, then in the Echo
MPLS Echo Request/Response messages. The LSP(s) under test are Request packet, the "Downstream IP Address" field, of the Downstream
identified using the RSVP P2MP IPv4 or IPv6 Session sub-TLVs Detailed Mapping TLV, MUST be set to the ALLROUTERs multicast
(see Section 3.1.1) or the Multicast LDP FEC Stack sub-TLV address.
(see Section 3.1.2).
Other sub-TLVs may be defined in other specifications to indicate If a Responder Identifier TLV is being used, then the Echo Request
the OAM procedures being bootstrapped, and to describe the bootstrap packet MAY reuse a received Downstream Detailed Mapping TLV.
parameters. Further details of the bootstrapping processes and the
bootstrapped OAM processes are described in other documents. For
example, see [MPLS-BFD] and [MCAST-CV].
5. Non-compliant Routers 4. Non-compliant Routers
If an egress for a P2MP LSP does not support MPLS LSP ping, then no If an egress for a P2MP LSP does not support MPLS LSP ping, then no
reply will be sent, resulting in a "false negative" result. There is reply will be sent, resulting in a "false negative" result. There is
no protection for this situation, and operators may wish to ensure no protection for this situation, and operators may wish to ensure
that end points for P2MP LSPs are all equally capable of supporting that end points for P2MP LSPs are all equally capable of supporting
this function. Alternatively, the traceroute option can be used to this function. Alternatively, the traceroute option can be used to
verify the LSP nearly all the way to the egress, leaving the final verify the LSP nearly all the way to the egress, leaving the final
hop to be verified manually. hop to be verified manually.
If, in "traceroute" mode, a transit node does not support LSP ping, If, in "traceroute" mode, a transit node does not support LSP ping,
then no reply will be forthcoming from that node for some TTL, say n. then no reply will be forthcoming from that node for some TTL, say n.
The node originating the echo request SHOULD continue to send echo The node originating the echo request SHOULD continue to send echo
request with TTL=n+1, n+2, ..., n+k to probe nodes further down the request with TTL=n+1, n+2, ..., n+k to probe nodes further down the
path. In such a case, the echo request for TTL > n SHOULD be sent path. In such a case, the echo request for TTL > n SHOULD be sent
with Downstream Mapping TLV "Downstream IP Address" field set to the with Downstream Detailed Mapping TLV "Downstream IP Address" field
ALLROUTERs multicast address as described in Section 3.3.4 until a set to the ALLROUTERs multicast address as described in Section 3.3.4
reply is received with a Downstream Mapping TLV. until a reply is received with a Downstream Detailed Mapping TLV.
6. OAM Considerations
5. OAM Considerations
The procedures in this document provide OAM functions for P2MP MPLS The procedures in this document provide OAM functions for P2MP MPLS
LSPs and may be used to enable bootstrapping of other OAM procedures. LSPs and may be used to enable bootstrapping of other OAM procedures.
In order to be fully operational several considerations must be made. In order to be fully operational several considerations must be made.
- Scaling concerns dictate that only cautious use of LSP Ping should - Scaling concerns dictate that only cautious use of LSP Ping should
be made. In particular, sending an LSP Ping to all egresses of a be made. In particular, sending an LSP Ping to all egresses of a
P2MP MPLS LSP could result in congestion at or near the ingress P2MP MPLS LSP could result in congestion at or near the ingress
when the responses arrive. when the responses arrive.
skipping to change at page 27, line 5 skipping to change at page 21, line 33
Such an interface SHOULD also provide the ability to disable all Such an interface SHOULD also provide the ability to disable all
active LSP Ping operations to provide a quick escape if the network active LSP Ping operations to provide a quick escape if the network
becomes congested. becomes congested.
- A MIB module is required for the control and management of LSP Ping - A MIB module is required for the control and management of LSP Ping
operations, and to enable the reported information to be inspected. operations, and to enable the reported information to be inspected.
There is no reason to believe this should not be a simple extension There is no reason to believe this should not be a simple extension
of the LSP Ping MIB module used for P2P LSPs. of the LSP Ping MIB module used for P2P LSPs.
7. IANA Considerations 6. IANA Considerations
7.1. New Sub-TLV Types 6.1. New Sub-TLV Types
Three new sub-TLV types are defined for inclusion within the LSP Ping Three new sub-TLV types are defined for inclusion within the LSP Ping
[RFC4379] Target FEC Stack TLV (TLV type 1). [RFC4379] Target FEC Stack TLV (TLV type 1).
IANA is requested to assign sub-type values to the following IANA is requested to assign sub-type values to the following
sub-TLVs from the "Multiprotocol Label Switching Architecture (MPLS) sub-TLVs from the "Multiprotocol Label Switching Architecture (MPLS)
Label Switched Paths (LSPs) Parameters - TLVs" registry, "TLVs and Label Switched Paths (LSPs) Parameters - TLVs" registry, "TLVs and
sub-TLVs" sub-registry. sub-TLVs" sub-registry.
RSVP P2MP IPv4 Session (see Section 3.1.1). Suggested value 17. RSVP P2MP IPv4 Session (see Section 3.1.1). Suggested value 17.
RSVP P2MP IPv6 Session (see Section 3.1.1). Suggested value 18. RSVP P2MP IPv6 Session (see Section 3.1.1). Suggested value 18.
Multicast LDP FEC Stack (see Section 3.1.2). Suggested value 19. Multicast P2MP LDP FEC Stack (see Section 3.1.2). Suggested value 19.
Multicast MP2MP LDP FEC Stack (see Section 3.1.2). Suggested value 20.
7.2. New Multipath Type
Section 3.3 of [RFC4379] defines a set of values for the LSP Ping
Multipath Type. These values are currently not tracked by IANA.
A new value for the LSP Ping Multipath Type is defined in Section
3.3.5 of this document to indicate that the reported Multipath
Information applies to a P2MP MPLS TE LSP.
IANA is requested to create a new registry as follows:
"Multiprotocol Label Switching Architecture (MPLS) Label Switched
Paths (LSPs) - Multipath Types"
Key Type Multipath Information
--- ---------------- ---------------------
0 no multipath Empty (Multipath Length = 0) [RFC4379]
2 IP address IP addresses [RFC4379]
4 IP address range low/high address pairs [RFC4379]
8 Bit-masked IP IP address prefix and bit mask [RFC4379]
address set
9 Bit-masked label set Label prefix and bit mask [RFC4379]
xx P2MP responder IP List of P2MP responders [thisDoc]
addresses
A suggested value of xx is 16.
New values from this registry are to be assigned only by Standards
Action.
7.3. New TLVs 6.2. New TLVs
Three new LSP Ping TLV types are defined for inclusion in LSP Ping Two new LSP Ping TLV types are defined for inclusion in LSP Ping
messages. messages.
IANA is requested to assign a new value from the "Multi-Protocol IANA is requested to assign a new value from the "Multi-Protocol
Label Switching Architecture (MPLS) Label Switched Paths (LSPs) Label Switching Architecture (MPLS) Label Switched Paths (LSPs)
Parameters - TLVs" registry, "TLVs and sub-TLVs" sub-registry as Parameters - TLVs" registry, "TLVs and sub-TLVs" sub-registry as
follows using a Standards Action value. follows using a Standards Action value.
P2MP Responder Identifier TLV (see Section 3.2.4) is a mandatory
TLV. Suggested value 11.
Two sub-TLVs are defined P2MP Responder Identifier TLV (see Section 3.2.4) is a mandatory
- Type 1: IPv4 P2MP Responder Identifier (see Section 3.2.4) TLV. Suggested value 11. Four sub-TLVs are defined.
- Type 2: IPv6 P2MP Responder Identifier (see Section 3.2.4) - Type 1: IPv4 Egress Address P2MP Responder Identifier
- Type 2: IPv6 Egress Address P2MP Responder Identifier
- Type 3: IPv4 Node Address P2MP Responder Identifier
- Type 4: IPv6 Node Address P2MP Responder Identifier
Echo Jitter TLV (see Section 3.2.5) is a mandatory TLV. Suggested Echo Jitter TLV (see Section 3.2.5) is a mandatory TLV. Suggested
value 12. value 12.
Node Properties TLV (see Section 3.2.2.1) is an optional TLV. 7. Security Considerations
Suggested value 32768.
Three sub-TLVs are defined
- Type 1: IPv4 Egress Address
- Type 2: IPv6 Egress Address
- Type 3: Branch Properties
7.4. New Return Code
A new Return Code is defined in Section 3.3.6.1.
IANA is requested to assign a new Return Code value for the "Multi-
Protocol Label Switching (MPLS) Label Switched Paths (LSPs)
Parameters" registry, "Return Codes" sub-registry as follows using a
Standards Action value.
Value Meaning
----- -------
TBD See DDM TLV for more details
Suggested value 14.
7.5. New Sub-TLV Value for the Downstream Detailed Mapping TLV
[DDMT] defines a TLV called the Downstream Detailed Mapping TLV and
requests IANA to maintain a registry of sub-TLVs that it can carry.
Section 3.3.6.1 of this document defines a new sub-TLV.
IANA is requested to assign a TLV type value as follows using a
Standards Action value from the range 0-32767.
Sub-Type Value Field
--------- ------------
TBD Return Code
8. Security Considerations
This document does not introduce security concerns over and above This document does not introduce security concerns over and above
those described in [RFC4379]. Note that because of the scalability those described in [RFC4379]. Note that because of the scalability
implications of many egresses to P2MP MPLS LSPs, there is a implications of many egresses to P2MP MPLS LSPs, there is a
stronger concern to regulate the LSP Ping traffic passed to the stronger concern to regulate the LSP Ping traffic passed to the
control plane by the use of a rate limiter applied to the LSP Ping control plane by the use of a rate limiter applied to the LSP Ping
well-known UDP port. Note that this rate limiting might lead to well-known UDP port. Note that this rate limiting might lead to
false positives. false positives.
9. Acknowledgements 8. Acknowledgements
The authors would like to acknowledge the authors of [RFC4379] for The authors would like to acknowledge the authors of [RFC4379] for
their work which is substantially re-used in this document. Also their work which is substantially re-used in this document. Also
thanks to the members of the MBONED working group for their review thanks to the members of the MBONED working group for their review
of this material, to Daniel King and Mustapha Aissaoui for their of this material, to Daniel King and Mustapha Aissaoui for their
review, and to Yakov Rekhter for useful discussions. review, and to Yakov Rekhter for useful discussions.
The authors would like to thank Vanson Lim, Danny Prairie, Reshad The authors would like to thank Vanson Lim, Danny Prairie, Reshad
Rahman, Ben Niven-Jenkins, Hannes Gredler, Nitin Bahadur, Tetsuya Rahman, Ben Niven-Jenkins, Hannes Gredler, Nitin Bahadur, Tetsuya
Murakami and Michael Hua for their comments and suggestions. Murakami, Michael Hua, Michael Wildt, Dipa Thakkar and IJsbrand
Wijnands for their comments and suggestions.
10. Intellectual Property Considerations
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any 9. References
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at ietf-
ipr@ietf.org.
11. Normative References 9.1 Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4379] Kompella, K., and Swallow, G., "Detecting Multi-Protocol [RFC4379] Kompella, K., and Swallow, G., "Detecting Multi-Protocol
Label Switched (MPLS) Data Plane Failures", RFC 4379, Label Switched (MPLS) Data Plane Failures", RFC 4379,
February 2006. February 2006.
[DDMT] Bahadur, N., Kompella, K., and Swallow, G., "Mechanism [DDMT] Bahadur, N., Kompella, K., and Swallow, G., "Mechanism
for Performing LSP-Ping over MPLS Tunnels", draft-ietf- for Performing LSP-Ping over MPLS Tunnels", draft-ietf-
mpls-lsp-ping-enhanced-dsmap, work in progress. mpls-lsp-ping-enhanced-dsmap, work in progress.
12. Informative References 9.2 Informative References
[RFC792] Postel, J., "Internet Control Message Protocol", RFC 792. [RFC792] Postel, J., "Internet Control Message Protocol", RFC 792.
[RFC4461] Yasukawa, S., "Signaling Requirements for Point to [RFC4461] Yasukawa, S., "Signaling Requirements for Point to
Multipoint Traffic Engineered Multiprotocol Label Multipoint Traffic Engineered Multiprotocol Label
Switching (MPLS) Label Switched Paths (LSPs)", Switching (MPLS) Label Switched Paths (LSPs)",
RFC 4461, April 2006. RFC 4461, April 2006.
[RFC4687] Yasukawa, S., Farrel, A., King, D., and Nadeau, T., [RFC4687] Yasukawa, S., Farrel, A., King, D., and Nadeau, T.,
"Operations and Management (OAM) Requirements for "Operations and Management (OAM) Requirements for
skipping to change at page 31, line 11 skipping to change at page 24, line 21
[BFD] Katz, D., and Ward, D., "Bidirectional Forwarding [BFD] Katz, D., and Ward, D., "Bidirectional Forwarding
Detection", draft-ietf-bfd-base, work in progress. Detection", draft-ietf-bfd-base, work in progress.
[MPLS-BFD] Aggarwal, R., Kompella, K., Nadeau, T., and Swallow, G., [MPLS-BFD] Aggarwal, R., Kompella, K., Nadeau, T., and Swallow, G.,
"BFD For MPLS LSPs", draft-ietf-bfd-mpls, work in "BFD For MPLS LSPs", draft-ietf-bfd-mpls, work in
progress. progress.
[IANA-PORT] IANA Assigned Port Numbers, http://www.iana.org [IANA-PORT] IANA Assigned Port Numbers, http://www.iana.org
13. Authors' Addresses 10. Authors' Addresses
Seisho Yasukawa Seisho Yasukawa
NTT Corporation NTT Corporation
(R&D Strategy Department) (R&D Strategy Department)
3-1, Otemachi 2-Chome Chiyodaku, Tokyo 100-8116 Japan 3-1, Otemachi 2-Chome Chiyodaku, Tokyo 100-8116 Japan
Phone: +81 3 5205 5341 Phone: +81 3 5205 5341
Email: s.yasukawa@hco.ntt.co.jp Email: s.yasukawa@hco.ntt.co.jp
Adrian Farrel Adrian Farrel
Old Dog Consulting Old Dog Consulting
skipping to change at page 32, line 5 skipping to change at page 25, line 11
Email: swallow@cisco.com Email: swallow@cisco.com
Thomas D. Nadeau Thomas D. Nadeau
British Telecom British Telecom
BT Centre BT Centre
81 Newgate Street 81 Newgate Street
EC1A 7AJ EC1A 7AJ
London London
Email: tom.nadeau@bt.com Email: tom.nadeau@bt.com
14. Full Copyright Statement Shaleen Saxena
Cisco Systems, Inc.
1414 Massachusetts Ave
Boxborough, MA 01719
Email: ssaxena@cisco.com
Copyright (C) The IETF Trust (2008). 11. Full Copyright Statement
This document is subject to the rights, licenses and restrictions Copyright (c) 2009 IETF Trust and the persons identified as the
contained in BCP 78, and except as set forth therein, the authors document authors. All rights reserved.
retain all their rights.
This document and the information contained herein are provided on an This document is subject to BCP 78 and the IETF Trust's Legal
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS Provisions Relating to IETF Documents in effect on the date of
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND publication of this document (http://trustee.ietf.org/license-info).
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS Please review these documents carefully, as they describe your rights
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF and restrictions with respect to this document.
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
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