Subject: [v6ops] new draft: draft-smith-v6ops-larger-ipv6-loopback-prefix

From: <[email-masked]>
Date: Mon, 30 Jul 2012 05:45:01 -0700 (PDT)

A new draft has been posted, at http://tools.ietf.org/html/draft-smith-v6ops-larger-ipv6-loopback-prefix. Please take a look at it and comment.

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From: Nick Hilliard <[email-masked]>
Date: Mon, 30 Jul 2012 15:35:52 +0100

On 30/07/2012 13:45, [email-masked] wrote:
> A new draft has been posted, at
> http://tools.ietf.org/html/draft-smith-v6ops-larger-ipv6-loopback-prefix.
> Please take a look at it and comment.

Overall I like this idea, but I don't think that sufficient justification
has been provided in the draft.

-  Regarding the justification in section 2,  #2.1 could in theory be
provided by private address space, but I see value here in terms of keeping
host-local traffic local.

I think the text could be tightened to say something like "we need a range
of loopback addresses for host-local requirements" where it can be
guaranteed by design that packets destined for a particular range of
addresses will not leave the machine (whether real or virtual).

-  Section 2.2 should be removed - there is nothing ipv4 related about the
use of 127.127/16 in ntpd.

-  you should consider whether RFC4379 should be mentioned in the
justification section and maybe talk to the MPLS people about this draft to
see if they're interested

-  I'm not sure section 2.3 provides a reasonably justification for a range
of loopbacks either.  In fact, I don't really understand what you're trying
to explain here.

-  Is there some reason that 0::/64 wouldn't suffice for this instead of
1::/48?  The reason for this is that it would automatically encompass the
existing loopback address which means that v6 hosts would only have to
increase the subnet mask from /128 to /64 in order to be compliant with
this draft.

Stylistically, the draft would be improved by cutting out about 70% of the
text.  There is implicit virtue in brevity and conciseness.  Could I
suggest the following changes?

-  amalgamate sections 3 and 4 into a single section section no more than a
couple of sentences long.

-  remove the ubiquitous references to 1::/48 and refer to the actual value
only in 2-3 instances at most.

-  amalgamate section 5 into two short paragraphs

-  security considerations: tl;dr.  Could this be made shorter?

Nick

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From: Philipp Kern <[email-masked]>
Date: Mon, 30 Jul 2012 17:04:39 +0200

> increase the subnet mask from /128 to /64 in order to be compliant with

Overlap with IPv6-compatible addressing[1] I presume.

Kind regards
Philipp Kern

[1] http://technet.microsoft.com/en-us/library/cc727992%28v=ws.10%29.aspx