On Tue, Jun 22, 2004 at 08:45:29AM +0200, Gert Doering wrote:
This doesn't fly. He can't set his own routing policy and he can't multihome. If he changes the single upstream his customers needs to renumber. As of today, "more-specific BGP multihoming" works. So he *can* set his own routing policy.
Maybe I have lost you somewhere now: You only get an assignement when you are a big one (>200 customers). That is to keep the routing table smaller. Because that does not work for small ISPs (see above) they announce a route for a smaller network (that was assigned to him from his upstream provider). So we have one /32 route less, one /40 route more or something like that. Doesn't seem to save much space in the routing table?
Admittedly, if changing the upstream, his customers would need to be renumbered (but this is not too different from IPv4 today with "very small ISPs that do not want to become LIR" - they use upstream space for a couple of years, and eventually become LIR and have to renumber).
It is an absolute pain in the ass. And it will be in the future. Yes, the mechanisms to make it easy are in place, but they are not implemented. Renumbering is NOT EASY. It costs a hell lot of money, each time it has to be done.
I can see that people don't like it, I'm just mentioning that it *could* be done. We will need to do something like that for the class "is ISP but is not LIR", even if we abandon the 200-users rule.
I would change that to "is mutlihomed but is not LIR". Even without being an ISP you can easily run into the same problems. And I do not want to be in charge at Siemens, GM, Nortel, Cisco or so for renumbering projects. With using globally unique addresses in the organization (and being able to do that is one of the advantages of IPv6 - using site local and NAT does not make sense, I can stay at v4 then) makes it even worse. Now renumbering of official Adresses "only" means changing everything about external communication. Nils