Hi.
Craig, all of the recent (post 1996) RFCs and IETF drafts that I have seen make it clear that address portability is inconsistent with having a routable Internet. The regional registries all have policies to reduce route table fragmentation by migrating organisations to provider addressing.
I'm suggesting we attempt to address historical address portability where it was rightfully assumed and that we do not attempt to force migration. Also clarification of the "ownership" of the NZGATE addresses would seem to be in order as there seems to be some dispute and confusion there.
I think Joe pretty much assumed that ISPs were aware of the potential problems with portability. If any of the major upstream providers of the New Zealand providers begin to filter small advertisements (say, smaller than /20) then a lot of NZ organisations with "portable" addresses could potentially be cut off from the rest of the world.
This is pretty unlikely. It would cut off major and important sections of the Internet, including most root name servers. Sprint unilaterally began filtering longer prefix routes several years ago but not those in ranges in use prior to widespread discussion of provider blocks (i.e. they have never filtered out NZGATE prefixes shorter than or equal to /24). Also, routing table growth has slowed because of the introduction of CIDR, the use of provider based addressing, and (proxy) aggregation. Routing table growth for the past three years (~1.7x) has been much slower than router CPU and memory growth and this trend is likely to continue. With it becoming increasingly easier to handle all routes, such action is now unlikely for technical reasons. The dampening used by some providers does tend to cause /24's to incur longer blocking than a /20 would as a result of flapping. But beyond this it's hard to see any potential problems with the portability of the NZGATE addresses (and many are in blocks larger than a /24 anyway).
You can be sure that many of these small routes are not carried globally and only have connectivity because the origin of the supernet routes gets the traffic close enough to a provider that doesn't filter.
For NZGATE addresses, i do not believe this is factual. In addition to my general moaning, the draft specifically penalises many older ISPs (by making the addresses of their servers non-portable) does not address multi-homed use, and does not provide exceptions where portability is reasonable. How about policies based more roughly around these ideas: Those who obtained addresses directly from Waikato with the legitimate understanding they were portable should be treated as portable (/23 or shorter automatically qualifies). Addresses obtained from an ISP are not portable and should not be advertised by another ISP (except by agreement). No provider is allowed to advertise supernets that overlap another providers advertisements (except by agreement). -Craig --------- To unsubscribe from nznog, send email to majordomo(a)list.waikato.ac.nz where the body of your message reads: unsubscribe nznog