[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: provider-int geo aggr [Re: plug: thesis on site multihoming]
On zondag, maa 30, 2003, at 18:51 Europe/Amsterdam, Pekka Savola wrote:
if a network
has four routers and wants to divide routing information for the IPv6
global unicast address space over those routers, it could have router
handle 2000::/5, router B 2800::/5, router C 3000::/5 and router D
3800::/5. So if this network peers with another network that announces
2200:abc::/35 and 3ffe:def::/35, all routers except router A filter
the first route, and all routers except router D filter out the second
route. When router C then has a packet for 2200:abc:1:2::1, it sends
packet to router A (because router A announces the 2000::/5 aggregate)
and router A delivers the packet to the right peer.
A,B,C,D are part of one AS. If you try to expand that so that they
aren't, you get into trouble.
And that's exactly the point: we aggregate inside provider networks.
Yes. But since no single router has to keep a copy of the entire DFZ
routing table, this is no longer a problem.
In the same way, if you don't expand it,
you are just solving the provider-internal problem -- and are requiring
the propagation of more specifics in DFZ.
It all boils down to the question: why would someone in Europe need
more specifics for people in the US, or vice versa?