draft-stewart-tsvwg-sctpipv6-00

Network Working Group R. R. Stewart
INTERNET-DRA S. Deering
Cisco
expires in six months June 1,2001
IPv6 addressing and Stream Control Transmission Protocol

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
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Abstract
Stream Control Transmission Protocol [RFC2960] provides transparent
multi-homing to its upper layer users. This multi-homing is
accomplished through the passing of address parameters in the
initial setup message used by SCTP. In an IPv4 network all addresses
are passed with no consideration for their scope and routeablility.
In a IPv6 network special considerations MUST be made to properly
bring up associations between SCTP endpoints that have IPv6
[RFC2460] addresses bound within their association. This document
defines those considerations and enumerates general rules
that an SCTP endpoint MUST use in formulating both the INIT and
INIT-ACK chunks.
Table Of Contents
1. Introduction
Stream Control Transmission Protocol [RFC2960] provides transparent
multi-homing to its upper layer users. This multi-homing is
accomplished through the passing of address parameters in the
initial setup message used by SCTP. In an IPv4 network all addresses
are passed with no consideration for their scope and routeablility.
In a IPv6 network special considerations MUST be made to properly
bring up associations between SCTP endpoints that have IPv6
[RFC2460] addresses bound within their association. This document
defines those considerations and enumerates general rules
that an SCTP endpoint MUST use in formulating both the INIT and
INIT-ACK chunks.
The emphasis in the rules laid out in this document are to prevent
an SCTP endpoint from listing an IPv6 address that is outside of its
routeable scope to a peer endpoint. This will prevent black-hole
conditions that may cause the unexpected failure of SCTP associations.
2. Conventions
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when
they appear in this document, are to be interpreted as described in
[RFC2119].
3. Special rules for IPv6 address

scoping
When selecting IPv6 addresses to include as parameters in the INIT
chunk the following rules MUST be applied:
A1) The INIT chunk SHOULD NOT include any IPv6 Link Local
address parameters unless the source or destination address
in the IPv6 header is a Link Local address.
A2) If IPv6 Link Local address parameters are included in the
INIT chunk, Link Local addresses that are NOT on the same
physical Link as that of the destination or source
IPv6 address (found in the IPv6 header) MUST NOT be included.
A3) The INIT chunk SHOULD NOT include any IPv6 Site Local
address parameters unless the source or destination address
in the IPv6 header is a Site Local address.
A4) If IPv6 Site Local addresses are included in the INIT chunk,
Site Local address that are NOT on the same site MUST NOT
be included.
A5) If the destination and source address of the INIT is an
IPv6 Global address then the sender SHOULD NOT include any
Site Local or Link Local IPv6 address parameters in the
INIT chunk.
When responding to an INIT chunk and selecting IPv6 address
parameters to be included in the INIT-ACK chunk, the following rules
MUST be applied:
B1) The INIT-ACK chunk SHOULD NOT include any IPv6 Link Local
address parameters unless the source or destination address
in the IPv6 header of the INIT chunk is a Link Local address.
B2) If IPv6 Link Local address parameters are included in the
INIT-ACK chunk, Link Local addresses that are NOT on the same
physical Link as the source or destination address in the
IPv6 header of the INIT chunk MUST NOT be included.
B3) The INIT-ACK chunk SHOULD NOT include any IPv6 Site Local
address parameters unless the source or destination address
in the IPv6 header of the INIT chunk is a Site Local address.
B4) If IPv6 Site Local addresses are included in the INIT-ACK
chunk, Site Local address that are NOT on the same site
as the received INIT chunk MUST NOT be included.

B5) If the destination and source address of the INIT is an
IPv6 Global address then the sender SHOULD NOT include any
Site Local or Link Local IPv6 address parameters in the
INIT-ACK chunk.
4. Authors addresses
Randall R. Stewart
24 Burning Bush Trail.
Crystal Lake, IL 60012
USA
Phone: +1 815 477 2127
EMail: rrs@
Stephen E. Deering
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-1706
USA
Phone: +1 408 527 8213
Fax: +1 408 527 8254
EMail: deering@
5. References
[RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, October 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2460] S. Dee

ring, R. Hinden, "Internet Protocol,
Version 6 (IPv6) Specification." December 1998.
[RFC2960] R. R. Stewart, Q. Xie, K. Morneault, C. Sharp,
H. J. Schwarzbauer, T. Taylor, I. Rytina, M. Kalla, L. Zhang,
and, V. Paxson, "Stream Control Transmission Protocol," RFC
2960, October 2000.