Bird 2.0 AS path prepending

20 Dec 2017

      Hello bird users,

I just started to test bird 2.0 and converted the existing bird 1.6
configuration to bird 2.0. I compiled bird 2.0.0 on my fedora test VM
and got it running. But when I use path prepending in BGP (the same way
I did in 1.6) bird throws an error and does not export the route. Does
anyone have the same problem?

Thanks,
Daniel

Configuration:

template bgp generic_bgp {
  local as 202739;
  enable route refresh on;
  keepalive time 10;
  hold time 30;
}

protocol bgp vultr from generic_bgp {
  neighbor 2001:19f0:ffff::1 as 64515;
  ipv6{
     next hop self;
     import keep filtered;
     import filter upstream_as64515_in;
     export filter upstream_out_test;
  };
  multihop 2;
  password "xxx";
}

filter upstream_out_test {
  if net = 2001:678:1e0::/48 then {
    bgp_path.prepend(202739);
    bgp_path.prepend(202739);
    bgp_path.prepend(202739);
    bgp_path.prepend(202739);
    accept;
  }

  reject;
}

Log:

Dec 20 17:47:51 bb1 bird[1370]: filters, line 110: Can't prepend to non-path

Bird 2.0 AS path prepending

Daniel Czerwonk