need help to use freebsd fib and bgp

[Benoit Chesneau]

Hi all,

What I am trying to achieve is to connect to remote peers using information found in fib1 routing table setup in freebsd and export / import routing information in this table using BGP. The issue I have right now is that this configuratin doesn't work. It can't connect to the remote A.B.C.0 ip and I get such errors in logs:

```
2023-06-06 02:05:58.571 <TRACE> enkiv4: A.B.C.D/24: ignored
2023-06-06 02:05:58.571 <TRACE> enkiv4: A.B.C.D/32: [alien] created
2023-06-06 02:05:58.571 <TRACE> enkiv4.ipv4 > added [best] A.B.C.D/32 0L 4G unicast
2023-06-06 02:05:58.571 <TRACE> enkiv4.ipv4 < rejected by protocol A.B.C.D/32 0L 4G unicast
```

Is this pattern expected to work? I am wondering if it's not an issue in Freebsd 13.2p0 version. I tried different combination these days without success. Any help would be much appreciated :) 

The connection used for bgp arrived on a vlan 20 on nic2 which I setup on fib1, while the management interface is on another nic (bge0) and get its IP using DHCP:

```
bge0 ---> fib 0 (used for management) DHCP
vlan20 -> fib 1 (connect to remote BGP peer) , static /31 IPV4
```

Here is a snippet of network setup:

```
# ifconfig bge0
bge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=c019b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,VLAN_HWTSO,LINKSTATE>
    ether 94:18:82:7b:88:20
    inet6 fe80::9618:82ff:fe7b:8820%bge0 prefixlen 64 scopeid 0x3
    inet 192.168.88.249 netmask 0xffffff00 broadcast 192.168.88.255
    media: Ethernet autoselect (1000baseT <full-duplex>)
    status: active
    nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>


# ifconfig vlan20
vlan2021: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=680703<RXCSUM,TXCSUM,TSO4,TSO6,LRO,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
    ether 50:65:f3:8b:98:71
    inet A.B.C.1 netmask 0xfffffffe broadcast 255.255.255.255
    inet6 fe80::5265:f3ff:fe8b:9871%vlan2021 prefixlen 64 scopeid 0xb
    groups: vlan
    vlan: 20 vlanproto: 802.1q vlanpcp: 0 parent interface: mlxen0
    fib: 1
    media: Ethernet autoselect (40Gbase-CR4 <full-duplex,rxpause,txpause>)
    status: active
    nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>

$ sudo netstat -rn4
Routing tables

Internet:
Destination        Gateway            Flags     Netif Expire
A.B.C.0/31    link#11            U      vlan2021
A.B.C.1       link#11            UHS         lo0
127.0.0.1          link#7             UHS         lo0
```

A minimal setup (edited for anonymization) in Bird is the following


```
   router id A.B.C.1;
   ipv4 table tabv4 sorted;


    protocol kernel enkiv4 {
            learn;
            kernel table 1;
            ipv4 {
                    table tabv4;
                    import all;
                    export all;
            };
    }

    protocol bgp transit_ipv4_1 {
        local A.B.C.1 as XXXX;
        neighbor A.B.C.0 as XXXX;
        default bgp_med 0;
        default bgp_local_pref 50;
        password "somepass";
        ipv4 {

            table tabv4;
            import keep filtered;
            import filter ebgp_import;
            export filter ebgp_export;
            next hop self;
        };
    };
```

routes that will be adverised are setup as blackhole routes directly in FreeBSD. Should I setup them using the static protocol?



Benoît