On Tue, Feb 25, 2025 at 12:39:29AM +0000, Nigel Kukard via Bird-users wrote: > Hi there, > > I'm wondering if someone can point out how the best path is being selected > below in Bird 3.0.1? > > In Bird v2 the route via 100.201.0.2 was selected. With the exact same > configuration in Bird v3, the route via 100.201.0.4 is being selected.
Hi I do not think this is really a change. If two routes have the same preference and are originated by the same protocol 'class' (e.g. BGP), they are compared using protocol-specific strategy (e.g. comparing bgp_local_pref, bgp_path length, ... in case of BGP). But in your case these two routes are from different protocols 'classes' (bgp_originate4 -> BGP a static4 -> Static), in that case there is only fixed arbitrary ordering, and that may changed between Bird v2 and v3. I would suggest that different protocol 'classes' should always use different preference. > In this case R1 is connected to R2. Both with the same ASN. The below table > is the table I have facing R2. > > In terms of my routing tables... > - originate4 =exports to=> bgp4 > - static4 =exports to=> master4 > - master4 <=exports/imports=> bgp4 > - bgp4 <=exports/imports=> t_bgp4_AS65000_r2_peer (below) > > > 1007-Table t_bgp4_AS65000_r2_peer: > 0.0.0.0/0 unicast [bgp_originate4 2025-02-24 23:21:13] * (200) > via 100.201.0.4 on eth2 > 1012- preference: 200 > source: static > bgp_local_pref: 930 > bgp_large_community: (65000, 3, 1) > 1008- Internal route handling values: 0L 24G 0S id 1 > 1007- unicast [static4 2025-02-24 23:21:13] (200) > via 100.201.0.2 on eth2 > 1012- preference: 200 > source: static > bgp_local_pref: 940 > bgp_large_community: (65000, 3, 1) (65000, 5000, 1) > 1008- Internal route handling values: 0L 22G 0S id 6 > > > Kind Regards > Nigel > -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santi...@crfreenet.org) "To err is human -- to blame it on a computer is even more so."
