Reporting issues

[Ondrej Zajicek]

On Sat, Apr 06, 2019 at 01:11:32PM -0600, Brian Topping 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.

Hi

Yes, this is proper place for reporting 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 <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 <https://github.com/danderson/metallb/issues/422> and the referenced PR.

Like Alexander Zubkov already noted, i also does not see any issue.

Mainly, the router ID and IP addresses are in general unrelated (although
BIRD defaults to using router ID based of one of its IP addresses when
router ID is not explicitly configured), so it is perfectly valid to have
session IP address different than router ID.


> Thanks for a great product!!

Thanks for the feedback.

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."