BIRD 2.0 on FreeBSD, multihop with multiple fibs

[Ondrej Zajicek]

On Fri, Dec 31, 2021 at 05:23:13PM +0000, Dominic Blais wrote:
> Hi,
> 
> I've had my load of issues with bird 2 on FreeBSD. I used BSDRP like 3 years ago and after an update I started having big issues related to bird.
> 
> I think BSDRP released version 1.98 with a fix for that.. don't know if it's ok in 1.99.
> 
> https://sourceforge.net/projects/bsdrp/files/BSD_Router_Project/1.98/
> "bird2: Fix multi-FIB usage by reverting bird commit 318acb0f6cb77a32aad5d7f79e06f3c5065ac702"

Hmm, not sure why they reverted this patch, that might break OSPF.

> ...
> In this setup, BIRD does not connect to 1.2.3.4 unless I manually add that host
> route to fib 0. Adding a % 'bge0.300' to the static route line doesn't change a
> thing, route still only appears in fib 1.
> 
> Two questions:
> 
>   - why does BIRD put the route in fib 1 when no fib is specified, and the
>     interface is not bound to a fib?

That is strange, BIRD should use 'table id' kernel protocol option to select
fib, and default should be 0. If you explicitly configure it to some other
value, say 2 or 3, are routes exported to fib 2 or 3?

(looking at the code seems to me that when fib is 0 then it is not
explicitly set for socket, so default would be used, and perhaps default
fib is inherited from parent process to be 1? But then, why would BGP
multihop resolve using fib 0 and not fib 1?)


-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
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"To err is human -- to blame it on a computer is even more so."