On Tue, Oct 02, 2001 at 09:58:56PM -0400, Jeff Mcadams wrote:
Is your position, honestly, that a provider the size of IgLou doesn't *deserve* to have robust network connectivity because we're not big enough? If so, I'll be sure to avoid purchasing any transit from you.
Aggregation vs. leaking specifics is about hierarchy -- the barrier of entry to announcing routes into the global BGP tables is very low -- a relatively small provider, with 1 router, in some corner of the world can cause bloat to the *global* tables and thereby force every other provider to share the cost of accomodating that bloat (likewise "big" providers who don't aggregate are also culpable, but also causing themselves pain, but they get compensated directly for that). Prefix length filtering is an interimn fix, an attempt, like import-duty to provide protection.
Also sprach Sean M. Doran
| Oh, and that scales really well.</sarcasm>
The solution to this is very simple: aggregate.
The entire ?LA scheme proposed for IPv6 smacks of the hierarchy; that those who build coast-to-coast or worldwide networks have _more_ of a right to introduce prefixes into the global table because they can aggregate better, and to some extent, that is a reality, that's the way it's going to have to be if the DFZ is going to be of a manageable size with current protocols. Unfortunately, even with a clear hierarchy, aggregation hides a lot of information about a given AS to peers and hot-potato routing forces even the bigger (in terms of total prefix space) providers to leak specifics to manage their traffic, but that can be worked out on a per-peer basis. *Luckily*, for the little guys, the "right" to multihome throws a wrench into the original IPv6 ?LA hierarchy model. However, so far, there is no realistic model that allows for a limited DFZ AND allows the leaking of specifics as required per the IPv4 multihoming model. I'm betting that a multiple address (prefix) host model, with something like SCTP will likely be the longterm "solution". Painful, but it moves the tragedy of the commons away from the network layer... Adi