Hi Brian,

Can you give specific examples of what is happening? Configuration
samples, show running route information from cli, etc.

On Sat, Apr 6, 2019 at 9:19 PM Brian Topping <[email protected]> wrote:
>
> Hi all, I think I looked in all the regular places and inferred that 
> reporting issues might best be done here. The gitlab issue tracker shows no 
> issues.
>
> The problem I have seen is where BIRD BGP is running a passive process. The 
> initiator peer is running the product at https://metallb.universe.tf. This 
> product can only initiate sessions. Due to (what I assume) is a bug in the 
> product, it was able to initiate a session from a TCP socket source address 
> that was not matched to the router ID. More specifically, both BGP processes 
> were running on the same host, with MetalLB configured to take a router ID 
> that was a secondary (internal / private) interface and and BIRD using the 
> primary interface address (so as to be able to connect to other external 
> peers).
>
> I believe the BIRD team would be interested in this because when BIRD BGP 
> accepted a connection with the same source address as it’s own Router ID, 
> even though the session provided a different router ID, it caused BIRD the 
> BIRD RIB and kernel exports to show the source of the route to be a 
> completely different BGP peer. In this case, the different peer was the 
> default route of a stub area, so incoming traffic to these addresses formed a 
> routing loop. It’s unclear to me whether this is a bug or a feature.
>
> If it is indeed a feature or unavoidable side effect that needs to be 
> supported all the same, what would have been desirable is if there was at 
> least some log message of the form “this is probably not what you want” when 
> a peer connected in this manner. More information can be found at 
> https://github.com/danderson/metallb/issues/422 and the referenced PR.
>
> I’m happy to help reproduce the problem if needed.
>
> Thanks for a great product!!
>
> best, Brian

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