bgp question

Justin M. Streiner streiner at
Wed Jan 11 00:58:09 UTC 2012

On Tue, 10 Jan 2012, Deric Kwok wrote:

> When we get  newip, we should let the upstream know to expor it as
> there should have rule in their side.

Correct.  Ideally, two things happen:
1. You tell your upstreams and peers about the new space, and they update 
whatever prefix filters they have in place for your network.
2. You update you own outbound BGP filters wherever necessary so that you 
can announce the new prefix, aggregated to the extent possible, when 
you're ready.

> how about upstream provider, does they need to let their all bgp
> interconnect to know those our newip?

They might.  It depends on the relationship your upstreams have with their 
neighbors.  Different providers have different criteria for what they'll 
accept and how they manage their filters.

If your upstreams need to have their upstreams and/or peers update their 
BGP filters, it is their responsibility to notify them.  Note that this 
can add to the amount of time it will take before your direct upstreams 
are ready to accept and propagate your new prefix.

Some providers might require that your new prefix be registered in one of 
several routing registries, and they'll update their filters based on your 
new registry data.


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