BGP routes not being propagated to kernel via OSPF

[Brian Topping]

If it helps, I uploaded the output from `debug backbone all` && `restart backbone` to https://gist.github.com/briantopping/7313d6bda963ea01b6d1288fda4942e8

> On Feb 17, 2020, at 12:17 AM, Brian Topping <brian.topping at gmail.com> wrote:
> 
> Greetings, I have a network with four routers on an OSPF backbone. Only one of the four routers cannot export the type 5 LSA entries to the kernel. I cannot figure out why. I wonder if I might kindly ask some guidance.
> 
> The routers (including the problem router) are all BIRD 2.0.7 with the router with IP 10.10.4.1 running 2.0.4. The kernels are Linux 4.20.x.
> 
> Here is the OSPF for a working router:
> 
>> protocol ospf backbone {
>>  ipv4 {
>>    export all;
>>    import filter { if net = 0.0.0.0/0 then reject; else accept; };
>>  };
>>  area 0.0.0.0 {
>>    interface "eno2" {};
>>    interface "vti*" {
>>      type nbma;
>>      strict nonbroadcast yes;
>>      neighbors {
>>        10.9.254.2 eligible;
>>      };
>>    };
>>  };
>> }
> 
> 
> 
> The OSPF configuration of the router having problems. They are virtually identical with the exception of the interfaces:
> 
>> protocol ospf backbone {
>>  ipv4 {
>>    export all;
>>    import filter { if net = 0.0.0.0/0 then reject; else accept; };
>>  };
>>  area 0.0.0.0 {
>>    interface "bond0" {
>>    };
>>    interface "vti*" {
>>      type nbma;
>>      neighbors {
>>        10.9.255.1 eligible;
>>        10.9.254.1 eligible;
>>      };
>>    };
>>  };
>> }
> 
> 
> All the routers have *identical* LSADBs  on each router (not shown). master4 is correct on the working routers:
>> [root at gw02 ~]# birdc show route
>> BIRD 2.0.7 ready.
>> Table master4:
>> 0.0.0.0/0            unicast [bgp_handy_125 02:07:43.248] * (100) [AS30475i]
>> 	via c.d.143.125 on eno1
>>                     unicast [bgp_handy_126 02:07:43.661] (100) [AS30475i]
>> 	via c.d.143.126 on eno1
>> a.b.96.0/32      unicast [backbone 02:07:46.207] E2 (150/10/10000) [c.d.143.113]
>> 	via 10.10.0.41 on eno2
>> a.b.96.9/32      unicast [backbone 02:07:46.207] E2 (150/10/10000) [c.d.143.113]
>> 	via 10.10.0.41 on eno2
>> a.b.96.8/32      unicast [backbone 02:07:46.207] E2 (150/10/10000) [c.d.143.113]
>> 	via 10.10.0.41 on eno2
>> a.b.96.11/32     unicast [backbone 02:07:46.207] E2 (150/10/10000) [c.d.143.113]
>> 	via 10.10.0.41 on eno2
>> 10.10.0.0/22         unicast [backbone 02:07:46.207] I (150/10) [c.d.143.113]
>> 	dev eno2
>> 10.9.254.2/32        unicast [backbone 02:08:16.208] I (150/10) [10.10.4.21]
>> 	via 10.9.254.2 on vti3
>> 10.9.254.0/24        unicast [backbone 02:08:16.208] I (150/10) [10.10.4.21]
>> 	dev vti3
>> 10.9.255.2/32        unicast [backbone 02:08:16.208] I (150/10) [10.10.4.21]
>> 	via 10.9.254.2 on vti3
>> 192.168.10.0/24      unicast [backbone 02:08:16.208] I (150/30) [10.10.4.1]
>> 	via 10.9.254.2 on vti3
>> 10.10.4.0/22         unicast [backbone 02:08:16.208] I (150/20) [10.10.4.1]
>> 	via 10.9.254.2 on vti3
>> 10.9.255.0/24        unicast [backbone 02:08:16.208] I (150/20) [c.d.143.113]
>> 	via 10.9.254.2 on vti3 weight 1
>> 	via 10.10.0.41 on eno2 weight 1
>> a.b.97.1/32      unicast [backbone 02:07:46.207] E2 (150/10/10000) [c.d.143.113]
>> 	via 10.10.0.41 on eno2
>> a.b.96.10/32     unicast [backbone 02:07:46.207] E2 (150/10/10000) [c.d.143.113]
>> 	via 10.10.0.41 on eno2
>> a.b.96.0/24      blackhole [public_nets_proto 02:07:35.107] * (500)
>>                     unicast [backbone 02:07:46.207] E2 (150/10/10000) [c.d.143.113]
>> 	via 10.10.0.41 on eno2
>> a.b.97.0/24      blackhole [public_nets_proto 02:07:35.107] * (500)
>>                     unicast [backbone 02:07:46.207] E2 (150/10/10000) [c.d.143.113]
>> 	via 10.10.0.41 on eno2
>> [root at gw02 ~]# birdc show route a.b.96.0/32 all
>> BIRD 2.0.7 ready.
>> Table master4:
>> a.b.96.0/32      unicast [backbone 02:07:46.207] E2 (150/10/10000) [c.d.143.113]
>> 	via 10.10.0.41 on eno2
>> 	Type: OSPF-E2 univ
>> 	OSPF.metric1: 10
>> 	OSPF.metric2: 10000
>> 	OSPF.tag: 0x00000000
>> 	OSPF.router_id: c.d.143.113
> 
> The router with problems does *not* have a correct copy of master4 table, it is missing all of the LSA type 5 entries. So of course they cannot be exported to kernel on that router:
>> [root at centos01 ~]# birdc show route
>> BIRD 2.0.7 ready.
>> Table master4:
>> 10.9.254.2/32        unicast [backbone 22:53:52.605] I (150/0) [10.10.4.21]
>> 	dev bond0
>> 10.9.254.0/24        unicast [backbone 00:08:15.604] I (150/10) [10.10.4.21]
>> 	dev bond0
>> 10.9.255.2/32        unicast [backbone 23:56:54.605] I (150/0) [10.10.4.21]
>> 	dev bond0
>> 192.168.10.0/24      unicast [backbone 22:54:32.604] I (150/20) [10.10.4.1]
>> 	via 10.10.4.1 on bond0
>> 10.10.4.0/22         unicast [backbone 22:54:32.604] I (150/10) [10.10.4.1]
>> 	dev bond0
>> 10.9.255.0/24        unicast [backbone 23:57:39.604] I (150/10) [c.d.143.113]
>> 	dev bond0
> 
> 
> What I cannot figure out is why the OSPF entries are not imported to master4 on this single machine. 
> 
> Thanks kindly for any thoughts.
> 
> Brian
> 
>