(IPng 5002) Re: Last Call: IP Version 6 Addressing Architecture to Proposed Standard
bmanning at ISI.EDU bmanning at ISI.EDU
Tue Dec 2 16:46:51 CET 1997
> 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
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