Re: [v6ops] draft-ietf-6man-rfc4291bis prohibiting non-/64 subnets

[Gert Doering <[e-mail]>]

Hi,

On Thu, Feb 23, 2017 at 07:00:13PM +0000, Nick Hilliard wrote:
> as it's currently worded, draft-ietf-6man-rfc4291bis seems to prohibit
> the implementation of any interface netmask != /64:
> 
> >                                           However, the Interface ID of
> >    all unicast addresses, except those that start with the binary value
> >    000, is required to be 64 bits long.
> 
> This has substantial operational consequences in the ipv6 world because
> if it's implemented as stated, it will cause production ipv6 networks to
> break.

Unless I'm totally mistaken this wording has been in "the appropriate
RFC" (4291?) since the beginning of time.

Well, 4291 only mentions this in passing, and points to 3587 [GLOBAL], 
which points to [ARCH] with this sentence

   [ARCH] also requires that all unicast addresses, except those that
   start with binary value 000, have Interface IDs that are 64 bits long
   and to be constructed in Modified EUI-64 format.

[ARCH] is 3513, and states

   For all unicast addresses, except those that start with binary value
   000, Interface IDs are required to be 64 bits long and to be
   constructed in Modified EUI-64 format.

which very much sounds like the sentence above.


> The ipv6 operational community may have opinions on the wisdom of
> mandating new behaviour which would cause their networks to fall over,
> so it would probably be a good idea to notify v6ops@ietf about the
> existence of this draft so that the folks over there get a look-in
> before a consensus call is made. As far as I can tell, this notification
> never happened.

It's not a new mandate - but doing this document, a discussion might
be in order on whether it should still be worded as strictly.

But since nobody seemed to care for the last 14 years (3513 is 
standard track, published April 2003), why should people or vendors
bother to follow RFC mandates now...?

Gert Doering
        -- NetMaster
-- 
have you enabled IPv6 on something today...?

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