nanog mailing list archives

Re: Getting a "portable" /19 or /20


From: Greg Maxwell <gmaxwell () martin fl us>
Date: Tue, 10 Apr 2001 16:30:22 -0400 (EDT)


On Tue, 10 Apr 2001, Joe Abley wrote:

On Tue, Apr 10, 2001 at 03:45:10PM -0400, Greg Maxwell wrote:

On Tue, 10 Apr 2001, Majdi S. Abbas wrote:

On Tue, Apr 10, 2001 at 08:27:54AM -0400, Greg Maxwell wrote:
The reason they don't allocate /24's is because without aggregation the
Internet is not scalable. Perhaps they are being too agressive, but the
reasoning is sound.

  Aggregation buys time, that's it.  Aggregation does not make the
current routing methods any more scalable.

In IPv4 yes, because you can't have perfect aggregation, too much network
multihoming and old prefixes and it's to painful to change address blocks.

In IPv6, if implimented right aggregation provides for virtually limitless
scalability for unicast traffic.

So long as "implemented right" means "edge sites are no longer
permitted to multi-home at the IP layer". If those are the
constraints of your routing policy, IPv4 will scale too. Very
nicely.

Well, thats close to what I ment. My proposal is that any networking
level multihoming for IPv6 not be globally advertised (I.e. two tier-2's
could fast path their networks to each other, and they both fully carry
the routing burden of that choice without impact to other networks). It should
be clairfied in the end-to-end multihoming draft soon.



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