wdiff draft-stewart-tsvwg-sctpipv6-00.txt draft-stewart-tsvwg-sctpipv6-01.txt

Network Working Group R. R. Stewart
INTERNET-DRA
INTERNET-DRAFT S. Deering
Cisco

expires in six months June 1,2001 April 10,2002

IPv6 addressing and Stream Control Transmission Protocol
<draft-stewart-tsvwg-sctpipv6-00>
<draft-stewart-tsvwg-sctpipv6-01.txt>

Status of This Memo

This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of [RFC2026]. 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.

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.

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

[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 ULP requests establishment of an SCTP association to a
IPv6 destination address, the following rules MUST be applied:

A1) The INIT chunk SHOULD NOT include any IPv6 Link Local
address parameters unless considerations apply:

- the source or requested destination address
in the IPv6 header is will be accompanied
by a Link Local address.

A2) If IPv6 Link Local address parameters are included in locally-significant "zone identifier" [scoped-addr-arch].

- 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 initial IPv6 header) packet (the packet
carrying the INIT) MUST NOT be included.

A3) The INIT chunk SHOULD NOT include any IPv6 Site Local an address parameters unless belonging to the source or
specified destination address
in the IPv6 header is a Site Local address.

A4) If IPv6 Site Local addresses are included in zone.

- the INIT chunk,
Site Local address that are NOT on the same site chunk MUST NOT
be included.

A5) If include all of, and only, the initiator's bound
addresses belonging to the destination zone and source address all larger,
encompassing zones, with the optional exception of the INIT is source address.

The receiver of an
IPv6 Global address then INIT will identify the sender SHOULD NOT include any
Site Local or Link Local IPv6 address parameters in relevant zone by the
INIT chunk.

When responding to an INIT chunk and selecting IPv6
scope of the source address
parameters and the arrival interface. In
choosing addresses to be included place 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
considerations apply:

- the IPv6 header receiver of the INIT chunk is a Link Local address.

B2) If IPv6 Link Local address parameters are included in will use the locally-significant
"zone identifier" [scoped-addr-arch] to scope the
INIT-ACK chunk, Link Local addresses that are NOT on
listed in the same
physical Link as INIT-ACK.

- the source or destination address in the initial IPv6 header of packet (the packet
carrying the INIT chunk INIT-ACK) MUST NOT be included.

B3) The INIT-ACK chunk SHOULD NOT include any IPv6 Site Local an address parameters unless belonging to 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 zone.

- 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 include all of, and only, the initiator's
bound addresses belonging to the destination zone and source address of the INIT is an
IPv6 Global address then all larger,
encompassing zones, with the sender SHOULD NOT include any
Site Local or Link Local IPv6 address parameters in optional exception of the
INIT-ACK chunk. source address.

4. Authors addresses
Randall R. Stewart
24 Burning Bush Trail.
Crystal Lake, IL 60012
USA
Phone: +1 815 477 2127
EMail: rrs@cisco.com

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@cisco.com

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. Deering, 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.

[scoped-addr-arch] S. Deering, B. Haberman, T Jinmei, E Nordmark,
A Onoe, B Zill, "IPv6 Scoped Address Architecture",
Work In Progress, November 2001.