What could be reason of route not propagating from LSA to routing table ?
Mariusz Gronczewski
xani+bird at devrandom.pl
Tue Feb 17 17:23:50 CET 2026
I have dug some more and tried to change network interface setting
on 10.30.1.0/31 RFC 3021 link (no broadcast), doesn't propagate route
on 10.30.1.1/30 link, doesn't propagate routes
on 10.30.1.1/29 link, propagates routes just fine
Similar setup "just works" in FRR so I'm now very confused on what is
happening.
Setup is 3 devices (other router and core L3 switches) all with
separate VLAN and /31 assigned to it.
Regards
Mariusz
On Wed, 11 Feb 2026 16:57:09 +0100
Mariusz Gronczewski <xani+bird at devrandom.pl> wrote:
> Hi,
>
> I'm trying to replace one of our Junipers and I've come up with
> bizzare problem.
>
> I'm trying to run OSPF instance on VRF (I don't think problem is VRF
> related, I tried without VRF and it's same result) and I see both
> peers and the LSA database are getting filled
>
> ☠ ip r sh vrf vrf-core
> 10.30.0.0/31 dev b-swcore.3011 proto kernel scope link src 10.30.0.0
> 10.30.0.4/31 dev b-swcore.3012 proto kernel scope link src 10.30.0.4
> 10.30.1.0/31 dev b-swcore.3000 proto kernel scope link src 10.30.1.0
>
> bird> show ospf neighbors
> core:
> Router ID Pri State DTime
> Interface Router IP 10.100.1.1 1 Full/PtP
> 37.905 b-swcore.3011 10.30.0.1 10.100.1.2 1
> Full/PtP 37.904 b-swcore.3012 10.30.0.5
> 193.200.227.2 128 Full/PtP 39.907
> b-swcore.3000 10.30.1.1
>
> bird> show ospf state
>
> area 0.0.0.0
>
> router 193.200.227.1
> distance 0
> router 10.100.1.1 metric 10
> router 10.100.1.2 metric 10
> router 193.200.227.2 metric 10
> stubnet 193.200.227.1/32 metric 0
> stubnet 10.30.1.0/31 metric 10
> stubnet 10.30.0.0/31 metric 10
> stubnet 10.30.0.4/31 metric 10
> stubnet 10.30.1.0/31 metric 10
> bird> show ospf topology
>
> area 0.0.0.0
>
> router 193.200.227.1
> distance 0
> router 10.100.1.1 metric 10
> router 10.100.1.2 metric 10
> router 193.200.227.2 metric 10
>
> bird> show protocols
> Name Proto Table State Since Info
> device1 Device --- up 2026-02-11 15:43:43.320
> kcore Kernel master4 up 2026-02-11 15:43:43.320
> core OSPF master4 up 2026-02-11 15:43:43.320
> Running
>
> (kcore is fetching from VRF kernel table to the main bird table)
>
> config is very bare bones
>
> protocol ospf core {
> vrf "vrf-core";
> ipv4 {
> import keep filtered on;
> import all;
> export all;
>
> };
> area 0 {
> interface "b-swcore.30*" {
>
> };
> interface "vrf-core" {
> stub;
> };
>
> };
>
> };
>
> protocol kernel kcore {
> kernel table 1002;
> learn all;
> ipv4 {
> export none;
> import all;
>
> };
>
> };
>
> but I'm only getting my own routes
>
> bird> show route
> Table master4:
> 10.30.1.0/31 unicast [core 2026-02-11 16:21:37.684] * I
> (150/10) [193.200.227.1] dev b-swcore.3000
> unicast [kcore 2026-02-11 16:21:38.584] (10)
> dev b-swcore.3000
> 10.30.0.0/31 unicast [core 2026-02-11 16:21:37.684] * I
> (150/10) [193.200.227.1] dev b-swcore.3011
> unicast [kcore 2026-02-11 16:21:38.584] (10)
> dev b-swcore.3011
> 10.30.0.4/31 unicast [core 2026-02-11 16:21:37.684] * I
> (150/10) [193.200.227.1] dev b-swcore.3012
> unicast [kcore 2026-02-11 16:21:38.584] (10)
> dev b-swcore.3012
> 193.200.227.1/32 unicast [core 2026-02-11 16:21:37.684] * I
> (150/0) [193.200.227.1] dev vrf-core
> bird>
>
>
>
>
> So far I tried running it outside of VRF and adding some PtP related
> options to OSPF but it didn't change anything I'm getting warnings
> about broadcast address
>
> Feb 11 16:21:37 d1-r1 bird[7194]: Missing broadcast address for
> interface b-swcore.3011 Feb 11 16:21:37 d1-r1 bird[7194]: Missing
> broadcast address for interface b-swcore.3012 Feb 11 16:21:37 d1-r1
> bird[7194]: Missing broadcast address for interface b-swcore.3000
>
> but those appear to be unrelated, I've changed one of the /31 links to
> /30 and nothing changed
>
> Version is 3.1.0 from Debian package but I also tried to downgrade to
> 2.x with no effect.
>
> The P2P links are just vlans to juniper and our 2 core switches
>
> on other side I also get no routes
>
> xani at r2> show ospf database advertising-router 193.200.227.1
>
> OSPF database, Area 0.0.0.0
> Type ID Adv Rtr Seq Age Opt
> Cksum Len Router 193.200.227.1 193.200.227.1 0x80000060
> 347 0x42 0xadd4 108
>
> while at same time getting some
>
> bird> show ospf lsadb router 193.200.227.1
>
> Area 0.0.0.0
>
> Type LS ID Router Sequence Age Checksum
> 0001 193.200.227.1 193.200.227.1 80000076 76 cd17
> bird> show ospf lsadb router 193.200.227.2
>
> Global
>
> Type LS ID Router Sequence Age Checksum
> 0005 88.156.75.236 193.200.227.2 8000c3e1 1249 3340
> 0005 193.200.227.2 193.200.227.2 8002a08f 2150 7d23
> 0005 194.50.132.0 193.200.227.2 80006374 1849 a24f
> 0005 194.50.134.0 193.200.227.2 80006374 648 8c63
> 0005 194.50.135.0 193.200.227.2 80006373 1549 836c
> 0005 212.91.10.200 193.200.227.2 800019e7 948 1b27
> 0005 0.0.0.0 193.200.227.2 80001b60 48 9334
> 0005 46.28.244.72 193.200.227.2 80018367 349 339f
>
> Area 0.0.0.0
>
> Type LS ID Router Sequence Age Checksum
> 0001 193.200.227.2 193.200.227.2 8002a1f5 87 074e
> 0002 10.30.1.1 193.200.227.2 80000001 87 427e
>
>
> I did try to run very simple equivalent OSPF config on FRR and it
> "just worked" so needless to say I'm very confused by the issue. Any
> ideas how I can even debug what's happening in the first place ?
>
> Regards
--
Mariusz Gronczewski (XANi) <xani+bird at devrandom.pl>
GnuPG: 0xEA8ACE64
https://devrandom.eu
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