BIRD 2.0.{7,10} MED not actually send for learned routes if export table on is set

[Ondrej Zajicek]

On Sun, Oct 16, 2022 at 11:17:23AM +0200, Inrin via Bird-users wrote:
> Greetings,
> 
> I noticed during setting up a peering that the MED is not actually send
> to my peer, although bird shows it in the export.
> We confirmed this via tcpdump on both ends.
> 
> After debugging a bit, I noticed that this only affects “learned” routes
> but routes from the static protocol worked just fine.
> 
> After disabling the “export table” feature, the MED was send out just
> fine.
> 
> Is this behaviour expected?

Hello

It is not expected behavior. Note that MED on route exported to EBGP
should be removed, unless it is explicitly set in the export filter. I
suspect that with export table, the attribute set in the export filter is
considered mistakenly as 'old' instead of 'fresh' for the purpose of MED
removal test, as the route is stored in the export table in-between.

-- 
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."