FreeBSD, multiple routing tables, "KRT: Error sending route 192.222.249.232/29 to kernel: File exists"

[Marek Zarychta]

W dniu 12.03.2022 o 16:48, Dan Mahoney pisze:
> Hey there,
>
> We've got a fairly simple setup where we have two fibs.  Interface routes are in both fibs the way BSD does it.  (Table 1 is the second fib, if it matters).

No, by default interface route is added only in interface fib for 
FreeBSD 13.0 and later. Setting "net.add_addr_allfibs=1" brings back old 
behavior.

> trying
> log syslog all;
>
> protocol kernel {
>      scan time 20;
>      ipv4 {
>          import all;
>          export all;
>          table master4;
>          };
>      kernel table 1;
>      }
>
> protocol kernel {
>      ipv6 {
>          import all;
>          export all;
>          table master6;
>          };
>      kernel table 1;
>      }
>
>
> protocol device {
>          scan time 10;
>          }
>
> setfib 1 netstat -nr:
>
> Routing tables (fib: 1)
>
> Internet:
> Destination        Gateway            Flags     Netif Expire
> default            192.222.249.233    UGS        bge0
> 127.0.0.1          link#5             UH          lo0
> 127.0.0.2          link#6             UH          lo1
> 192.222.249.232/29 link#1             U          bge0
>
> fib 0 would be the same.
>
> An old thread seemed to imply this was because the "direct" protocol was missing.
>
> Adding the "direct" protocol doesn't stop this error every 20 seconds in syslog (which seems to be related to the scan time).
>
> Mar 12 15:24:11 box1 bird[34463]: KRT: Error sending route 192.222.249.232/29 to kernel: File exists
> Mar 12 15:24:31 box1 bird[34463]: KRT: Error sending route 192.222.249.232/29 to kernel: File exists
> Mar 12 15:24:51 box1 bird[34463]: KRT: Error sending route 192.222.249.232/29 to kernel: File exists
> Mar 12 15:25:11 box1 bird[34463]: KRT: Error sending route 192.222.249.232/29 to kernel: File exists
> Mar 12 15:25:31 box1 bird[34463]: KRT: Error sending route 192.222.249.232/29 to kernel: File exists
>
> Is it possible bird isn't differentiating routes learned from each fib and is learning from both, separately, and not properly deduplicating those routes?
>
> -Dan

What FreeBSD version are you running? FreeBSD routing stack has been 
significantly rewritten for 13.0-RELEASE, moreover this rewritten 
routing stack in stable/13 was polished a bit, so if you are 
encountering this on 13.0-RELEASE, then please upgrade to 13.1-BETA.

You can also probably either:

1. Filter this route to prevent it from being added.

2. Disable aforementioned  "net.add_addr_allfibs".

-- 
Marek Zarychta