Hello all,
I am getting cornered into a case where may never happen but still I am trying to be prepared.
In RTBH use-case the NLRIs (not important which Address Family) are usually advertised as /32 from a remote PE and normally they arrive via iBGP.
In the following example I'll be using L3VPN terms.
The RTBH NLRI's arrive with a community to indicate that they should be treated specifically and applied as drop routes
But at the PE there are "real" routes coming from a PE-CE protocol e.g. eBGP.
In case both are /32 the local routes will be selected at the VRF level or at the global BGP level and RTBH will not work.
router bgp 100
vrf tomer
neighbor 121.121.121.2
address-family ipv4 unicast
route-policy RTBH in
route-policy RTBH
if community matches-any (100:667) then
set administrative-distance 1
set next-hop discard
end-policy
!
That configuration was not accepted - under BGP
!!% Could not find entry in list: Policy [new] uses the 'administrative-distance' attribute. There is no 'administrative-distance' attribute at the bgp neighbor-in-vrf attach point.
So does anyone know how it can be solved?
I did see some hacks in another thread that by specially writing an ACL.
But I am looking for a dynamic behavior.
Any ideas?
Regards,
Egon
