Network Working Group Naiming Shen Internet Draft Redback Networks Expiration Date: December 2003 June 2003 Link Name and Sequence Options for IPv6 Neighbor Discovery draft-shen-ipv6-nd-name-seq-options-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 troubleshooting and management in IPv6 environment, two new options for IPv6 Neighbor Discovery messages are proposed in this document. The Link-Name option is used in Router Advertisement message, and the Sequence-Number option is used in Neighbor Solicitation and Neighbor Advertisement messages. 3. Introduction The Router Advertisement message in Neighbor Discovery for IPv6 [1] currently has defined options with source link-layer address, MTU and prefix information. It is obvious that, by inspecting a link-local address of the neighbor from diagnostics information is less clear than symbolic names. This draft proposes a mechanism allowing Router Advertisement message to include a Link-Name option. Shen Expires December 2003 [Page 1] Internet Draft IPv6 ND Link-Name and Seq-Num June 2003 When Neighbor Advertisement message is received from a neighbor, and if the Neighbor Solicitation messages were retransmitted, it is useful from troubleshooting point of view to learn which Neighbor Solicitation message the Neighbor Advertisement message replied to and what is the round trip delay for this address resolution, similar to the sequence number and round-trip time scheme used in ICMP request/reply implementation. 4. Link-Name Option The Link-Name option MAY be included in Router Advertisement message. A typical Link-Name can be a combination of router name, virtual router identifier and interface name of the link. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Link-Name String .... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Fields: Type Link-Name [TBD: IANA] Length 6 (including the type and length fields, total 48 bytes) Link-Name String This field identifies the symbolic name of the link of the router. The string is null-terminated if the name is less than 46 bytes. The option MUST be silently ignored for other Neighbor Discovery messages. 5. Sequence-Number Option The Sequence-Number option MAY be included in Neighbor Solicitation message and Neighbor Advertisement message. The sequence number is maintained for each cache entry and is increased by one for each Neighbor Solicitation sent for the entry. A Neighbor Advertisement message only include this option when responding to the Neighbor Solicitation message, and it SHOULD simply copy the Sequence-Number Option from the Neighbor Solicitation packet unchanged. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Sequence-Number | Shen Expires December 2003 [Page 2] Internet Draft IPv6 ND Link-Name and Seq-Num June 2003 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NS User Data | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Fields: Type Sequence-Number [TBD: IANA] Length 1 (8 bytes including the type and length fields) Sequence-Number A 16-bit unsigned integer in network byte order. NS User Data A 32-bit unsigned integer in network byte order. This value has only local significance to the sender of the Neighbor Solicitation packet. For example, it can be a timestamp in milliseconds. The option SHOULD only be used in Neighbor Solicitation message when the source address is not an unspecified address. The Neighbor Advertisement SHOULD relay the option back to the sender of the Neighbor Solicitation packet when responding to the Neighbor Solicitation. This option SHOULD not be used in unsolicited Neighbor Advertisement message. 6. Security Considerations This extension does not introduce any security issues. 7. Acknowledgments TBD. 8. References [1] Narten, T., Nordmark, E. and W. Simpson, "Neighbor Discovery for IP Version 6 (IPv6)", RFC 2461, December 1998. 9. Author Information Naiming Shen Redback Networks, Inc. 300 Holger Way San Jose, CA 95134 e-mail: naiming@redback.com Shen Expires December 2003 [Page 3]