Re: [v6ops] PI [ULA draft revision #2 Regarding isolated networks]

[Owen DeLong <[e-mail]>]

> 
>> Yes, we need to change the fundamental way we deal with routing and come
>> up
>> with a more scalable solution than the current everyone knows every
>> prefix
>> model.
>> 
> <tp>
> Owen,
> 
> yes, and that is what the RRG did.  It came up with two solutions and,
> being an IRTF and not an IETF WG, one solution was declared appropriate
> while the other (LISP) is being developed by the IETF:-)

Not sure why your mailer can’t do quoting correctly, but I’ve fixed it here
for you.

> 
> The key to both is that while the number of prefixes is likely to grow
> beyond the capacity of routers, the number of locations involved is
> likely to remain much smaller so that routing will be based on
> locations, with a mapping from prefix to location prior to routing.

LISP is way over-complicated for the problem space in question, though it’s
probably the right general idea.

In reality, what is needed is a simpler solution probably related to doing
the IDR portion of routing on destination ASN. Unfortunately, we don’t have
a good way in the current protocol to encode the destination ASN onto the
packet. My thinking is that a revised 44 octet header would do the trick and
that during the transition process, having routers that border between
44-octet header capable zones and non-44-octet header capable zones would
perform the header replacement. Unfortunately, this has PMTU-D issues which
I haven’t figured out how to address yet.

Owen

> 
> All in the RRG archives.
> 
> Tom Petch
> 
> However, at any likely growth rate, if we actually start working on the
> problem
> instead of simply inflicting limitations and calling it handled, then we
> have
> time to address the issue in IPv6. Hopefully the RRG will wake up and
> start
> addressing this issue. For now, it is out of scope for v6ops as I
> understand
> the WG charter.
> 
>> And I think that every SME who has lost business with the
> unreliability
>> of their ISP will want multi-homing and will think that with IPv6 and
> PI
>> the constraints have gone, and the number of such SMEs can only
> approach
>> 10M over time.
> 
> All the more reason this issue needs to get addressed instead of
> ignored.
> 
>> So, Brian is spot on, and just as the IETF did little about IPv4
>> addresses running out until the event loomed large, so I expect
> history
>> to repeat itself with the growth of PI in IPv6.
> 
> He’s somewhat right about the problem. He’s absolutely wrong in
> believing that
> the current limitations are a solution.
> 
> Owen
>