OSPF wireguard fallback

[chrono]

Hi Ondrej,

thanks for the quick reply.

>> What makes me wonder is why wg0 is coming up as stubnet here,
>> while the MPLS links come up as network (stubnet 172.23.3.0/29 metric 
>> 10)
>> and 172.23.3.0/29 (wg0 net) not being listed.

> You don't see 172.23.3.0/29 as network, because these ifaces are
> configured as PtP, but still there should be 'router' line in 
> apropriate
> router block to indicate existing PtP link.

Yes, while trying to debug someone on #BIRD (freenode) suggested that
it may not work due to wg0 not being a broadcast interface:

wg0       Link encap:UNSPEC  HWaddr 
00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
           inet addr:172.23.3.1  P-t-P:172.23.3.1  Mask:255.255.255.248
           UP POINTOPOINT RUNNING NOARP  MTU:1420  Metric:1
           RX packets:102368 errors:0 dropped:0 overruns:0 frame:0
           TX packets:103213 errors:10189 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:14697260 (14.6 MB)  TX bytes:14771860 (14.7 MB)

I checked bird docs and found the interface configuration option type
and tried to set it to pointtopoint but with no success so far. Which
would be the correct setting for a wireguard interface?

> So apparently there is no association. You should check by 'show ospf
> neighbors' and use tcpdump to verify if each neighbor hears the other
> one.

Correct:

bird> show ospf neighbors
MyOSPF:
Router ID       Pri          State      DTime   Interface  Router IP
192.168.148.1     1     Full/BDR        00:34   macsec.2334 172.23.2.2
192.168.148.1     1     Full/BDR        00:34   macsec.2335 172.23.1.2

On both sides I only see the periodic:

14:41:00.172942 IP (tos 0xc0, ttl 1, id 13458, offset 0, flags [none], 
proto OSPF (89), length 96)
     172.23.3.2 > 224.0.0.5: OSPFv2, Hello, length 60 [len 44]
         Router-ID 192.168.148.1, Backbone Area, Authentication Type: MD5 
(2)
         Key-ID: 3, Auth-Length: 32, Crypto Sequence Number: 0x000852b4
         Options [External]
           Hello Timer 10s, Dead Timer 40s, Mask 255.255.255.248, 
Priority 1

05:37:43.772608 IP (tos 0xc0, ttl 1, id 12083, offset 0, flags [none], 
proto OSPF (89), length 96)
     172.23.3.1 > 224.0.0.5: OSPFv2, Hello, length 60 [len 44]
         Router-ID 192.168.184.1, Backbone Area, Authentication Type: MD5 
(2)
         Key-ID: 3, Auth-Length: 32, Crypto Sequence Number: 0x000c1abe
         Options [External]
           Hello Timer 10s, Dead Timer 40s, Mask 255.255.255.248, 
Priority 1