Re: (IPng 5002) Re: Last Call: IP Version 6 Addressing Architecture to Proposed Standard
- Date: Tue, 2 Dec 1997 07:46:51 -0800 (PST)
- Posted-date: Tue, 2 Dec 1997 07:46:51 -0800 (PST)
> 1) We are not there yet. Andrew Brodnik et al demonstrated that one can
> efficiently compress today's routing tables in the cache of a Pentium
> chip. But their algorithm has yet to be implemented in commercial
> routers.
True. But how far off can that be? :)
> 2) There is more to scaling than routers' caches. Compressing the tables
> in cache memory mainly allows you to switch packets faster than if your
> tables were kept in a slow RAM. It does not reduce route flaps, or
> the complexity of the topology.
One of the interesting side effects from the paper is the construct
that appears to allow the creation of a true default free router
i.e. one that has the ability to carry the total IPv4 space as
host routes.
a 13bit TLA does not reduce route flap nor moderate the complexity
of the topology, which appear to have moved into the critical path.
a 13bit TLA does give some breathing room by sanctioning a level
of proxy aggregation. This method allows ISPs to lie to each
other about the stability of their internal infrastructure, which
is the current model for reducing the dynamics of the routing system.
(Is it just me or is there really a joke being perpetrated by
the attempts to present a stable routing infrastructure with dynamic
routing protocols? :)
> 3) In any case, we are taking decision today based on today's technology.
> As I pointed out, there is plenty of address space reserved for further
> use. If the technology does evolve, then it will be time to open
> more space.
Fine. Then this might be best served as a BCP and not standards
track? Or are the concerns rasied by everyone but me strong
enough to push this into the standards track? What I find interesting
is that this particular addressing scheme has had less field time
than the previous addressing scheme. Will there be yet another
scheme fall out of the woodwork? Is there a reason why these
schemes can't co-exist?
And I'm not sure that the extra space will be available. Are you?
>
> In short, limiting the size of TLA to 13 bits looks like a reasonable cut,
> today.
Ok. I just thought I'd say my piece.
>
> --
> Christian Huitema
>
--
--bill
