LLGR De-Preferencing

[Matt Corallo]

Oops, duh, thanks!

On 12/1/25 12:54 PM, Maria Matejka wrote:
> Hello Matt,
> 
> your preference attribute is manually set higher which takes precedence over anything specified in BGP.
> 
> If you want LLGR to work, keep both sessions at the same preference and set only bgp_local_pref 
> which is evaluated after LLGR. Yes, these are different attributes.
> 
> Maria
> 
> On Mon, Dec 01, 2025 at 12:13:14PM -0500, Matt Corallo wrote:
> 
>     It appears bird (2.17.1) doesn’t implement the required LLGR de-preferencing logic, eg in a
>     simple test environment with LLGR and one (otherwise-preferred) session down, bird shows it as
>     still selected even though it has the stale flag (see below). Is there any way to do the
>     required de-preferencing with filters or would a patch to implement this be simple?
> 
>     Thanks.
> 
>     bird> show route for 69.59.18.0 all Table master4: 69.59.18.0/24 unicast [localsyncb
>     17:06:58.262 from 10.242.243.12] * (101s) [AS397444i] Type: BGP univ BGP.origin: IGP
>     BGP.as_path: 397444 BGP.next_hop: …. BGP.local_pref: 101 BGP.community: (65535,6) unicast
>     [localsync 2025-11-30 from 10.242.242.12] (100) [AS397444i] Type: BGP univ BGP.origin: IGP
>     BGP.as_path: 397444 BGP.next_hop: …. BGP.local_pref: 100
> 
> –
> Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o.
>