draft-ietf-mpls-icmp-07.txt   draft-ietf-mpls-icmp-08.txt 
MPLS Working Group R. Bonica MPLS Working Group R. Bonica
Internet-Draft D. Gan Internet-Draft D. Gan
Intended status: Standards Track Juniper Networks Intended status: Standards Track Juniper Networks
Expires: June 15, 2007 D. Tappan Expires: August 4, 2007 D. Tappan
C. Pignataro C. Pignataro
Cisco Systems, Inc. Cisco Systems, Inc.
December 12, 2006 January 31, 2007
ICMP Extensions for MultiProtocol Label Switching ICMP Extensions for MultiProtocol Label Switching
draft-ietf-mpls-icmp-07 draft-ietf-mpls-icmp-08
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes 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. 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
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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."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
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The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
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This Internet-Draft will expire on June 15, 2007. This Internet-Draft will expire on August 4, 2007.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2006). Copyright (C) The IETF Trust (2007).
Abstract Abstract
This memo defines an extension object that can be appended to This memo defines an extension object that can be appended to
selected multi-part ICMP messages. This extension permits Label selected multi-part ICMP messages. This extension permits Label
Switching Routers to append MPLS information to ICMP messages, and Switching Routers to append MPLS information to ICMP messages, and
has already been widely deployed. has already been widely deployed.
Table of Contents Table of Contents
1. Conventions Used In This Document . . . . . . . . . . . . . . . 3 1. Conventions Used In This Document . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Application to TRACEROUTE . . . . . . . . . . . . . . . . . . . 4 3. Application to TRACEROUTE . . . . . . . . . . . . . . . . . . . 4
4. Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. MPLS Label Stack Object . . . . . . . . . . . . . . . . . . . . 5 5. MPLS Label Stack Object . . . . . . . . . . . . . . . . . . . . 5
6. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
8. Normative References . . . . . . . . . . . . . . . . . . . . . 7 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7
Intellectual Property and Copyright Statements . . . . . . . . . . 9 Intellectual Property and Copyright Statements . . . . . . . . . . 9
1. Conventions Used In This Document 1. 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 RFC2119 [RFC2119]. document are to be interpreted as described in RFC2119 [RFC2119].
2. Introduction 2. Introduction
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source hosts. Network operators use this information to diagnose source hosts. Network operators use this information to diagnose
routing problems. routing problems.
When a router receives an undeliverable IP datagram, it can send an When a router receives an undeliverable IP datagram, it can send an
ICMP message to the host that originated the datagram. The ICMP ICMP message to the host that originated the datagram. The ICMP
message indicates why the datagram could not be delivered. It also message indicates why the datagram could not be delivered. It also
contains the IP header and leading payload octets of the "original contains the IP header and leading payload octets of the "original
datagram" to which the ICMP message is a response. datagram" to which the ICMP message is a response.
MPLS Label Switching Routers (LSR) also use ICMP to convey control MPLS Label Switching Routers (LSR) also use ICMP to convey control
information to source hosts. Sections 2.3 and 2.4 of [RFC3032] information to source hosts. Section 2.3 of [RFC3032] describes the
describe the interaction between MPLS and ICMP. interaction between MPLS and ICMP, and Sections 2.4 and 3 of
[RFC3032] provide applications of that interaction.
When an LSR receives an undeliverable MPLS encapsulated datagram, it When an LSR receives an undeliverable MPLS encapsulated datagram, it
removes the entire MPLS label stack, exposing the previously removes the entire MPLS label stack, exposing the previously
encapsulated IP datagram. The LSR then submits the IP datagram to an encapsulated IP datagram. The LSR then submits the IP datagram to an
error processing module. Error processing can include ICMP message error processing module. Error processing can include ICMP message
generation. generation.
The ICMP message indicates why the original datagram could not be The ICMP message indicates why the original datagram could not be
delivered. It also contains the IP header and leading octets of the delivered. It also contains the IP header and leading octets of the
original datagram. original datagram.
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ICMP Extension Structure Header and an ICMP Object Header. Both are ICMP Extension Structure Header and an ICMP Object Header. Both are
defined in [I-D.bonica-internet-icmp]. defined in [I-D.bonica-internet-icmp].
The ICMP extension defined in this document is equally applicable to The ICMP extension defined in this document is equally applicable to
ICMPv4 [RFC0792] and ICMPv6 [RFC4443]. Throughout this document, ICMPv4 [RFC0792] and ICMPv6 [RFC4443]. Throughout this document,
unless otherwise specified, the acronym ICMP refers to multi-part unless otherwise specified, the acronym ICMP refers to multi-part
ICMP messages, encompassing both ICMPv4 and ICMPv6. ICMP messages, encompassing both ICMPv4 and ICMPv6.
3. Application to TRACEROUTE 3. Application to TRACEROUTE
The ICMP extensions defined in this memo support enhancements to The ICMP extension defined in this memo supports enhancements to
TRACEROUTE. Enhanced TRACEROUTE applications, like older TRACEROUTE. Enhanced TRACEROUTE applications, like older
implementations, indicate which nodes the original datagram visited implementations, indicate which nodes the original datagram visited
en route to its destination. They differ from older implementations en route to its destination. They differ from older implementations
in that they also reflect the original datagram's MPLS encapsulation in that they also reflect the original datagram's MPLS encapsulation
status as it arrived at each node. status as it arrived at each node.
Figure 1 contains sample output from an enhanced TRACEROUTE Figure 1 contains sample output from an enhanced TRACEROUTE
implementation. implementation.
> traceroute 192.0.2.1 > traceroute 192.0.2.1
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message. message.
Figure 2 depicts the MPLS Label Stack Object. It must be preceded by Figure 2 depicts the MPLS Label Stack Object. It must be preceded by
an ICMP Extension Structure Header and an ICMP Object Header. Both an ICMP Extension Structure Header and an ICMP Object Header. Both
are defined in [I-D.bonica-internet-icmp]. are defined in [I-D.bonica-internet-icmp].
In the object payload, octets 0-3 depict the first member of the MPLS In the object payload, octets 0-3 depict the first member of the MPLS
label stack. Each remaining member of the MPLS label stack is label stack. Each remaining member of the MPLS label stack is
represented by another 4 octets that share the same format. represented by another 4 octets that share the same format.
MPLS Label Stack Class = 1, C-Type = 1. Class-Num = 1, MPLS Label Stack Class
C-Type = 1, Incoming MPLS Label Stack
Length = 4 + 4 * (number of MPLS LSEs)
0 1 2 3 0 1 2 3
+-------------+-------------+-------------+-------------+ +-------------+-------------+-------------+-------------+
| Label |EXP |S| TTL | | Label |EXP |S| TTL |
+-------------+-------------+-------------+-------------+ +-------------+-------------+-------------+-------------+
| | | |
| // Remaining MPLS Stack Entries // | | // Remaining MPLS Label Stack Entries // |
| | | |
+-------------+-------------+-------------+-------------+ +-------------+-------------+-------------+-------------+
Figure 2: MPLS Label Stack Object Figure 2: MPLS Label Stack Object
Label: 20 bits Label: 20 bits
Exp: Experimental Use, 3 bits Exp: Experimental Use, 3 bits
S: Bottom of Stack, 1 bit S: Bottom of Stack, 1 bit
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extension that allows an MPLS router to append MPLS information to extension that allows an MPLS router to append MPLS information to
multi-part ICMP messages, and therefore can provide the user of the multi-part ICMP messages, and therefore can provide the user of the
traceroute application with additional information. Consequently, a traceroute application with additional information. Consequently, a
network operator may wish to provide this information selectively network operator may wish to provide this information selectively
based on some policy; for example, only include the MPLS extensions based on some policy; for example, only include the MPLS extensions
in ICMP messages destined to addresses within the network management in ICMP messages destined to addresses within the network management
blocks with administrative control over the router. An blocks with administrative control over the router. An
implementation could determine whether to include the MPLS Label implementation could determine whether to include the MPLS Label
Stack extensions based upon the destination address of the ICMP Stack extensions based upon the destination address of the ICMP
message, or based on a global configuration option in the router. message, or based on a global configuration option in the router.
Alternativelly, an implementation may determine whether to include Alternatively, an implementation may determine whether to include
these MPLS extensions when TTL expires based on the number of label these MPLS extensions when TTL expires based on the number of label
stack entries (depth of the label stack) of the incoming packet. stack entries (depth of the label stack) of the incoming packet.
Finally, an operator can make use of the TTL treatment on MPLS Pipe Finally, an operator can make use of the TTL treatment on MPLS Pipe
Model LSPs defined in [RFC3443] for a TTL-transparent mode of Model LSPs defined in [RFC3443] for a TTL-transparent mode of
operation, that would prevent ICMP Time Exceeded altogether when operation, that would prevent ICMP Time Exceeded altogether when
tunneled over the MPLS LSP. tunneled over the MPLS LSP.
7. IANA Considerations 7. IANA Considerations
IANA is requested to assign the following object Class-num in the IANA is requested to assign the following object Class-num in the
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MPLS Label Stack Class Sub-types: MPLS Label Stack Class Sub-types:
C-Type Description C-Type Description
1 Incoming MPLS Label Stack 1 Incoming MPLS Label Stack
0xF7-0xFF Reserved for private use 0xF7-0xFF Reserved for private use
C-Type values are assignable on a first-come-first-serve (FCFS) basis C-Type values are assignable on a first-come-first-serve (FCFS) basis
[RFC2434]. [RFC2434].
8. Normative References 8. References
8.1. Normative References
[I-D.bonica-internet-icmp] [I-D.bonica-internet-icmp]
Bonica, R., "Modifying ICMP to Support Multi-part Bonica, R., "Extended ICMP to Support Multi-part
Messages", draft-bonica-internet-icmp-13 (work in Messages", draft-bonica-internet-icmp-16 (work in
progress), December 2006. progress), January 2007.
[RFC0792] Postel, J., "Internet Control Message Protocol", STD 5, [RFC0792] Postel, J., "Internet Control Message Protocol", STD 5,
RFC 792, September 1981. RFC 792, September 1981.
[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.
[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 2434, IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998. October 1998.
[RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y., [RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y.,
Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack
Encoding", RFC 3032, January 2001. Encoding", RFC 3032, January 2001.
[RFC4443] Conta, A., Deering, S., and M. Gupta, "Internet Control
Message Protocol (ICMPv6) for the Internet Protocol
Version 6 (IPv6) Specification", RFC 4443, March 2006.
8.2. Informative References
[RFC3034] Conta, A., Doolan, P., and A. Malis, "Use of Label [RFC3034] Conta, A., Doolan, P., and A. Malis, "Use of Label
Switching on Frame Relay Networks Specification", Switching on Frame Relay Networks Specification",
RFC 3034, January 2001. RFC 3034, January 2001.
[RFC3035] Davie, B., Lawrence, J., McCloghrie, K., Rosen, E., [RFC3035] Davie, B., Lawrence, J., McCloghrie, K., Rosen, E.,
Swallow, G., Rekhter, Y., and P. Doolan, "MPLS using LDP Swallow, G., Rekhter, Y., and P. Doolan, "MPLS using LDP
and ATM VC Switching", RFC 3035, January 2001. and ATM VC Switching", RFC 3035, January 2001.
[RFC3443] Agarwal, P. and B. Akyol, "Time To Live (TTL) Processing [RFC3443] Agarwal, P. and B. Akyol, "Time To Live (TTL) Processing
in Multi-Protocol Label Switching (MPLS) Networks", in Multi-Protocol Label Switching (MPLS) Networks",
RFC 3443, January 2003. RFC 3443, January 2003.
[RFC4443] Conta, A., Deering, S., and M. Gupta, "Internet Control
Message Protocol (ICMPv6) for the Internet Protocol
Version 6 (IPv6) Specification", RFC 4443, March 2006.
Authors' Addresses Authors' Addresses
Ronald P. Bonica Ronald P. Bonica
Juniper Networks Juniper Networks
2251 Corporate Park Drive 2251 Corporate Park Drive
Herndon, VA 20171 Herndon, VA 20171
US US
Email: rbonica@juniper.net Email: rbonica@juniper.net
Der-Hwa Gan Der-Hwa Gan
Juniper Networks Juniper Networks
1194 N. Mathilda Ave. 1194 N. Mathilda Ave.
Sunnyvale, CA 94089 Sunnyvale, CA 94089
US US
Email: dhg@juniper.net Email: dhg@juniper.net
Daniel C. Tappan Daniel C. Tappan
Cisco Systems, Inc. Cisco Systems, Inc.
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Carlos Pignataro Carlos Pignataro
Cisco Systems, Inc. Cisco Systems, Inc.
7025 Kit Creek Road 7025 Kit Creek Road
Research Triangle Park, N.C. 27709 Research Triangle Park, N.C. 27709
US US
Email: cpignata@cisco.com Email: cpignata@cisco.com
Full Copyright Statement Full Copyright Statement
Copyright (C) The Internet Society (2006). Copyright (C) The IETF Trust (2007).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property Intellectual Property
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
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made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
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