Network Working Group Enke Chen
Internet Draft Naiming Shen
Expiration Date: December 2003 Redback Networks
Carry the ifIndex Number In Certain ICMP and ICMPv6 Messages
draft-chen-icmp-ifindex-00.txt
1. Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
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2. Abstract
To facilitate network debugging we propose that the ifIndex number be
carried in the ICMP/ICMPv6 "Time Exceeded Message" and "Destination
Unreachable Message (port unreachable)".
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3. Introduction
The source address in the "Time Exceeded Message" and "Destination
Unreachable Message (port unreachable)" of ICMP [1] and ICMPv6 [2] is
usually the IP/IPv6 address of an interface of a router/host on which
the packet arrived. This address (as displayed by the network
management tool "traceroute") is essential for network operators to
identify and debug specific forwarding paths in a network.
When un-numbered interfaces are involved, however, the source address
alone would not be enough in determining the incoming interface of a
packet. This presents a significant hurdle for network management.
To facilitate network debugging, we propose that the ifIndex [3] be
carried in the ICMP/ICMPv6 "Time Exceeded Message" and "Destination
Unreachable Message (port unreachable)".
4. Carry the ifIndex Number
Each of the ICMP/ICMPv6 "Time Exceeded Message" [1, 2] and
"Destination Unreachable Message (port unreachable)" has a 32-bit
field that is labeled "unused" in the ICMP and ICMPv6 specifications.
We propose that the ifIndex [3] be carried in the 32-bit "unused"
field. The ifIndex number should be for the incoming interface of the
packet.
As defined in [3], the ifIndex is an unique, non-zero, constant value
for an interface, and it is of local significance.
It is optional to carry the ifIndex number in the specified
ICMP/ICMPv6 messages. The field must be zero when the ifIndex number
is not carried.
5. Security Considerations
This extension does not introduce any security issues.
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6. Acknowledgments
TBD.
7. References
[1] J. Postel, "Internet Control Message Protocol", RFC 792,
September 1981.
[2] A. Conta, S. Deering, "Internet Control Message Protocol (ICMPv6)
for the IPv6 Specification", Work in Progress, draft-ietf-ipngwg-
icmp-v3-02.txt, November 2001.
[3] K. McCloghrie, F. Kastenholz, "The Interfaces Group MIB", RFC
2863, June 2000.
8. Author Information
Enke Chen
Redback Networks, Inc.
350 Holger Way
San Jose, CA 95134
e-mail: enke@redback.com
Naiming Shen
Redback Networks, Inc.
350 Holger Way
San Jose, CA 95134
e-mail: naiming@redback.com
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