route server appears to be selecting preferred routes and not all routes

[Daniel Suchy]

Hello,
that's expected behavior of BGP. There's extension to BGP described in
RFC 7911 allowing multiple paths to be advertised to eBGP peers, in Bird
you can try "add paths" configuration option (but this also requires
capabality support on other side).

With regards,
Daniel

On 8/21/18 12:05 PM, alarig at swordarmor.fr wrote:
> Hi Stephen,
> 
> 21 août 2018 00:17 "Stephen Fromm" <stephenf at nero.net> a écrit:
>> We are running bird as a route server to support a small IX. The
>> challenge we are having is that it appears that bird is selecting a
>> preferred route from what is advertised to the route servers and then
>> advertising back out only the preferred route to all members, instead of
>> advertising all routes received for a given network. Included below are
>> relevant configuration snippets, logs, and some show commands.
>>
>> How do I configure bird to keep the routes learned from all peers and
>> advertise those back out to the members and not select a preferred
>> route?
> 
> It’s a normal behaviour, only the preferred route is announced to other peers.
> 
> We have the same here:
> bird> show route 192.175.48.0/24
> 192.175.48.0/24    via 185.1.89.16 on eth2 [bgp_as112 2018-08-18] * (100) [AS112i]
>                    via 185.1.89.12 on eth2 [bgp_quantic 2018-08-18] (100) [AS112i]
>                    via 185.1.89.13 on eth2 [bgp_grifon_budic 2018-08-18] (100) [AS112i]
> bird> show route export bgp_izzycom where net ~ [ 192.175.48.0/24 ]
> 192.175.48.0/24    via 185.1.89.16 on eth2 [bgp_as112 2018-08-18] * (100) [AS112i]
> 
> I just displayed one route in my example, but it’s the same for the others.
>