[c-nsp] Redistribute customer network in BGP

[Marco Matarazzo]

> hello all,

Hi Prit!

> How can redistribute the network which i received from my customer
> with his AS number to my upstream provider ?

It should be automatic. If you have a route in your bgp table, it will be
forwarded to all you peers, if filter lists, routemaps and prefix-lists
allow for it.

Here's an example:

router bgp 12345
 no synchronization
 bgp router-id myRouter IP
 bgp cluster-id 3641938978
 bgp log-neighbor-changes
 network myNetwork

 neighbor myUpstream remote-as 11111
 neighbor myUpstream prefix-list myUpstreamPrefixOUT out
 neighbor myUpstream filter-list myUpstreamACLOUT out
 neighbor myUpstream route-map myUpstreamOUT out

 neighbor myUpstream prefix-list myUpstreamPrefixIN in
 neighbor myUpstream filter-list myUpstreamACLIN in
 neighbor myUpstream route-map myUpstreamIN in


 neighbor downstreamCustomer remote-as 22222
 neighbor downstreamCustomer prefix-list customerPrefixIN in
 neighbor downstreamCustomer filter-list customerACLIN in
 neighbor downstreamCustomer route-map customerRoutemapIN in

 neighbor downstreamCustomer prefix-list customerPrefixOUT out
 neighbor downstreamCustomer filter-list customerACLOUT out
 neighbor downstreamCustomer route-map customerRoutemapOUT out

Now, for you customer you'll have to configure what you allow him to inject
into your BGP table (with prefix-list you specify what prefixes, with filter
list, which BGP Paths, with route-maps you can change the behaviour of a
certain route) and what you'll send him.

You'll have to configure the same for the upstream, so make sure that the
prefix list on the upstream matches also che customers IP addresses, and
that you're not disallowing it in the routemap.

Check with a:

show ip bgp neighbor UpstreamIPAddress advertised-routes

if you're announcing all the prefixes.

If you're not advertising them, it's a problem with the above mentioned
prefix-lists, filter-lists or route-maps.

 If you're advertising that correctly, the upstream is probably filtering
them. This could be because:

a) You don't have the routes registered in any Routing Registry, and your
upstream requires it (i.e. it's a requirement for Level3).
b) You didn't advise your upstream that you were going to add some prefixes
and paths, so they did not update their filters.

In these case, a call to their bgp support department should solve the
problems immediately.

Cheers,
]\/[arco