Filtering prefixes longer than /24

[Pekka Savola]

On Tue, 10 Jul 2001 itojun@iijlab.net wrote:
> >You're right; it's not a complete non-issue, but I feel it's very safe to
> >assume that at least 10,000 routes can be handled just fine.  Building
> >IPv6 routing archtitecture on the fact that aggregation is very aggressive
> >and DFZ has only e.g. less than 500 routes or the like would probably lead
> >to some sort of CIDR disaster.
>
> 	who is going to decide whether you are within the first 10000
> 	(lucky) routes, or you are outside of it and now can't advertise?

Currently full 6bone routing table is like 260 routes (if not filtered).
Filtered to the maximum, it's like 160.

By allowing something I don't think it immediately means everyone starts
doing so.  By defining the limit just so, the increase might not even be
that significant.

> 	there are other multihoming mechanisms that does not impact worldwide
> 	routing table size.  for example, draft-ietf-ipngwg-ipv6-2260-01.txt
> 	and some others.  you may want to try these.
> 	(but "multihoming" is rather a vague term, so the goals may be
> 	different by who you talk to - the goals of the above draft is
> 	clearly stated in the draft)

This only protects from YourOrg-ISP link failure.  Often you might want to
protect from routing failures of your ISP too, or set preference when
using multiple peers (e.g. if your ISP's peering gets too bad).

Anyway.. this doesn't seem to be going anywhere so I guess we'll just
start to use the RIR assigned /35 more aggressively and flush out the
6bone /32.

-- 
Pekka Savola                 "Tell me of difficulties surmounted,
Netcore Oy                   not those you stumble over and fall"
Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords