On Mon, Sep 19, 2022 at 01:23:28PM +0000, Mazur, Dariusz via Bird-users wrote: > Hello, > In my setup I have iBGP session with peer , and I learn v6 route. It is iBGP > so we have 2 next hops global and link-local. By default bird uses link-local > when route is exported to kernel. Is there any command to change this > behavior and use global v6 address as BGP next hop when we export routes to > kernel ?
Hello The dual next hop for IPv6 routes is kind of hack and not really reflected in filter code, which means that bgp_next_hop attribute represents just global address. Therefore, you can do: bgp_next_hop = bgp_next_hop; in remote IBGP export filter to reset bgp_next_hop attribute to just its global address. I think it would not work in local IBGP import filter - we assign recursive immediate next hop based on bgp_next_hop when route is received before import filter, so later change of bgp_next_hop in IBGP import filter would not affect existing immediate next hop. You can also change immediate next hop (route attribute 'gw'), either in local IBGP import filter, or Kernel protocol export filter: gw = bgp_next_hop; but that would work only if you have flat network and there is no intermediate hop between local system and bgp_next_hop. We probably should just add option to ignore link-local BGP next hops ... > Table master6: > fc00:2001:100:12::/64 unicast [2001:4878:c225::1:3:2__r02.ien.labkrk01.sdn > 12:57:29.076] * (100) [i] > via 2001:4878:c225::1:3:2 on eth-1\1\4 > Type: BGP univ > BGP.origin: IGP > BGP.as_path: > BGP.next_hop: 2001:4878:c225::1:3:2 fe80::1:3:2 > BGP.local_pref: 400 > BGP.community: (20940,550) > > Thanks, > Dariusz -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santi...@crfreenet.org) OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) "To err is human -- to blame it on a computer is even more so."
