[c-nsp] BGP routes disappearing

[Saku Ytti]

I don't think there is enough information here to understand the problem.

So you have

RouterA - RouterB

RouterA is 192.0.2.1/24
RouterB is 128.139.197.146

RouterB advertises bunch of /32s to routerA, with next-hop 192.0.2.1?

This seems nonsensical to me, where is routerA supposed to send the
packets? So I must be misunderstanding what you're doing.

But you probably can look at the disappeared routers in adjRIB for
some clue, or turn on debugging on BGP, to see why they are
invalidated.

I'm expecting invalid next-hop, next-hop loop or BGP session itself
has the most-specific route to the BGP session over the BGP session.




On Mon, 10 Jun 2024 at 11:09, Hank Nussbacher via cisco-nsp
<cisco-nsp at puck.nether.net> wrote:
>
> I have a simple iBGP peer defined as follows:
>
>   neighbor 128.139.197.146
>    remote-as 378
>    update-source Loopback0
>    address-family ipv4 unicast
>
>
> I have a GigE interface defined as:
>
> interface GigabitEthernet0/0/0/43.1
>   ipv4 address 192.0.2.1 255.255.255.0
>   encapsulation dot1q 1
>
> This iBGP peer feeds me /32s with nexthop set as 192.0.2.1/32. Problem
> is all routes disappear.
>
> Neighbor        Spk    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down
> St/PfxRcd
> 128.139.197.146   0   378   10437  627880 10060119    0    0
> 00:15:41          0
>
>
> If the feed sets the IP to 192.0.2.2 then the BGP routes appear in the
> routing table.  If I then change the IP address on interface
> GigabitEthernet0/0/0/43.1 to 192.0.2.2 then the routes disappear as well
> after having made it into the routing table.
>
>
> I am obviously missing something very simple.  Clue-bat welcome.
>
>
> Thanks,
>
> Hank
>
>
>
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-- 
  ++ytti