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. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as ``work in progress.'' The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. 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)". Chen & Shen [Page 1] Internet Draft draft-chen-icmp-ifindex-00.txt June 2003 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. Chen & Shen [Page 2] Internet Draft draft-chen-icmp-ifindex-00.txt June 2003 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 Chen & Shen [Page 3]