Subject: I-D Action: draft-ietf-6man-segment-routing-header-23.txt

From: [email-masked]
Date: Mon, 16 Sep 2019 20:55:24 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the IPv6 Maintenance WG of the IETF.

        Title           : IPv6 Segment Routing Header (SRH)
        Authors         : Clarence Filsfils
                          Darren Dukes
                          Stefano Previdi
                          John Leddy
                          Satoru Matsushima
                          Daniel Voyer
	Filename        : draft-ietf-6man-segment-routing-header-23.txt
	Pages           : 32
	Date            : 2019-09-16

Abstract:
   Segment Routing can be applied to the IPv6 data plane using a new
   type of Routing Extension Header called the Segment Routing Header.
   This document describes the Segment Routing Header and how it is used
   by Segment Routing capable nodes.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-6man-segment-routing-header/

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-ietf-6man-segment-routing-header-23
https://datatracker.ietf.org/doc/html/draft-ietf-6man-segment-routing-header-23

A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-ietf-6man-segment-routing-header-23

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

---

From: "Darren Dukes (ddukes)" <[email-masked]>
Date: Tue, 17 Sep 2019 04:02:26 +0000

This version addresses some editorial and minor changes based on the IESG review including:
Liang Xie - minor edits
Alexey Melnikov - BCP38 reference
Magnus Westerlund’s -indicate HMAC verification failure results in drop

Darren

> On Sep 16, 2019, at 11:55 PM, [email-masked] wrote:
> 
> 
> --------------------------------------------------------------------
> IETF IPv6 working group mailing list
> [email-masked]
> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
> --------------------------------------------------------------------

---

From: Mark Smith <[email-masked]>
Date: Tue, 17 Sep 2019 14:58:55 +1000

Hi,

I really think this ID should be strongly recommending the use of the
Unique Local Unicast Address space (RFC 4193) for the outer tunnel
addressing used for the SR function.

It's specifically designed and intended for local network limited
traffic. Consequently, it is clearly invalid traffic if it leaks onto
the Internet, which can't as easily be said about GUA addressed
traffic. ULA traffic's ability to travel very far across the Internet
is inherently limited.

Furthermore, it has a 40 bit global ID portion that is required to be
likely globally unique via an algorithm ("Unique" Local Unicast
Address space). That means than in a scenario where two SR networks
are joined together e.g. carrier-to-carrier SR, each of their unique
/48 ULA prefixes can be routed into the others' network without
requiring renumbering or any form of IPv6 NAT.

(For some more background on ULAs, I recently did a presentation at
the AusNOG conference on getting them right, as some people have been
treating them as exact equivalents of RFC 1918s, and making them
non-unique - "Ausnog 2019 - Getting IPv6 Private Addressing Right" -
https://www.slideshare.net/MarkSmith214/ausnog-2019-getting-ipv6-private-addressing-right
)

Regards,
Mark.