Configure mutliple ip-next-hop in a policy route-map

[Aminiok]

Hi,
Is it possible to set mutliple (a list of) next-hops in a policy route-map? I suppose the answer is no [https://github.com/FRRouting/frr/blob/575a0c5e3cdc50915a9c41ab9a2c5ff31ff7e04d/bgpd/bgp_routemap.c#L1890]?

[donaldsharp]

The current answer is no. Would be a good addition though if someone were to add it

[ton31337]

Outgoing direction? You might be able to do this with two conditions: match prefix-list + match something-else, set ip next-hop. But I didn't look at the code if that would work or not.

[Aminiok]

Yes, set ip next-hop works only with one next-hop and not a list of next-hops.

[Aminiok]

Something like that:
route-map sth... permit 1
match ip address prefix-list sth..
set ip next-hop 10.0.0.1 10.0.0.2

[ton31337]

How it will know which one to assign for the prefixes?

[Aminiok]

Could you elaborate your question?

[donaldsharp]

@ton31337 -> He's asking for an ecmp nexthop group. As such bgp should be made aware of the nexthop group cli ( see sharpd code ) and it should be installing the routes to zebra as nexthop groups. There are abunch of little things that need to be done here. But the gist of it is that there should be a new set command set nexthop-group FOO Where foo is the cli that spells out the nexthop group. It's a decent amount of work though. And also requires several other things to come together.

[ton31337]

Ah, now I see.

[Aminiok]

Thanks @donaldsharp for your answer. Here the idea is to use the routemap in an export rule to make the FRR to advertise two next_hop for the same network (NLRI).
For example, network 192.168.1.0/24 being accessible via two paths 10.1.0.1 and 10.2.0.1, the update message sent to the peers for this NLRI (192.168.1.0/24) will contain two next_hop attributes (10.1.0.1 and 10.2.0.1).

[ton31337]

Is there any other vendor implementation of the thing you are asking for?