What could cause 0.0.0.0 (inaccessible) from 0.0.0.0 (<my loopback IP>) in FRR bgpd

[Peter Olsson]

Hello!

I run FRR 7.5.1-1.1 in Debian 11.3.

I am trying to convert a quagga router to a frr router.
I have come to the point that all BGP peers are up, and ospfd/ospf6d seem fine.

But I can't advertise my own networks in BGP, because of this:
  Local
    0.0.0.0 (inaccessible) from 0.0.0.0 (<my loopback IP>)
      Origin IGP, metric 0, weight 32768, invalid, sourced, local

This problem applies to both connected interfaces and static routes.

I can't see the problem in my configuration and there are too many
BGP peers and interfaces to anonymize all of it to be able to upload it.
There are no confederations or reflectors, just a lot of ebgp peers and
some ibgp peers in a full mesh.

The frr logs don't seem to contain anything useful, and google
just gives me years old entries for that message or similar.

Where should I start looking for the problem?


bgpd> sh ip bg x.y.z.46
BGP routing table entry for x.y.z.0/23
Paths: (2 available, best #1, table default)
  Advertised to non peer-group peers:
  xxx
  Local
    <ibgp peer> (metric 40) from <ibgp peer> (<ibgp peer>)
      Origin IGP, metric 0, localpref 100, valid, internal, best (First path received)
      Last update: Mon Mar 28 03:48:31 2022
  Local
    0.0.0.0 (inaccessible) from 0.0.0.0 (<my loopback IP>)
      Origin IGP, metric 0, weight 32768, invalid, sourced, local
      Last update: Mon Mar 28 03:47:50 2022

zebra> sh ip route x.y.z.46
Routing entry for x.y.z.32/27
  Known via "ospf", distance 110, metric 40
  Last update 01:09:24 ago
    <ospf neighbor, same as ibgp peer>, via enp196p0.107, weight 1

Routing entry for x.y.z.32/27
  Known via "connected", distance 0, metric 0, best
  Last update 01:09:41 ago
  * directly connected, enp196p0.519

zebra> sh ip route <my loopback IP>
Routing entry for <my loopback IP>/32
  Known via "connected", distance 0, metric 0, best
  Last update 00:57:29 ago
  * directly connected, lo

htgr01-zebra> sh ip route 0.0.0.0
Routing entry for 0.0.0.0/0
  Known via "ospf", distance 110, metric 40
  Last update 00:58:54 ago
    <ibgp peer>, via enp196p0.107, weight 1

Routing entry for 0.0.0.0/0
  Known via "static", distance 1, metric 0, best
  Last update 00:59:11 ago
  * x2.y2.z2.78, via veth-S, weight 1


Thanks!

Peter Olsson