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-01.txt
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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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.
1. 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.
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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.
2. Neighbor Discovery Option Additions
Two new options for Neighbor Discovery are defined in this
document, the Link-Name option and the Sequence-Number option.
2.1 Link-Name Option
The Link-Name option MAY be included in Router Advertisement
message. A typical Link-Name may 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 103, Link-Name [TBD: IANA]
Length 1-32 (8 to 256 bytes including the type and length
fields)
Link-Name String
This field identifies the symbolic name of the link
on the router. The string is null-terminated if the
actual length of the name is less than specified.
The option MUST be silently ignored for other Neighbor Discovery
messages.
2.2 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 includes this option when responding to the Neighbor
Solicitation message, and it MUST simply copy the Sequence-Number
Option from the Neighbor Solicitation packet unchanged if it
supports this extension.
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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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NS Local Data ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Fields:
Type 104, Sequence-Number [TBD: IANA]
Length 1-32 (8 to 256 bytes including the type and length
fields)
Sequence-Number
A 16-bit unsigned integer in network byte order.
NS Local Data
This data has only local significance to the sender
of the Neighbor Solicitation packet. For example, it
can contain 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.
3. Security Considerations
This document has no known security implications.
4. IANA Considerations
The author has chosen "103" as the type code for Link-Name option,
and "104" as the type code for Sequence-Number option. Those need
to be allocated by IANA.
5. Acknowledgments
TBD.
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6. Normative References
[1] Narten, T., Nordmark, E. and W. Simpson, "Neighbor Discovery
for IP Version 6 (IPv6)", RFC 2461, December 1998.
7. Author Information
Naiming Shen
Redback Networks, Inc.
300 Holger Way
San Jose, CA 95134
e-mail: naiming@redback.com
8. Full Copyright Statement
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