Posted on January 13, 2020 5:03 pm
 |  Asked by sowmya krishnaswamy
Print Friendly, PDF & Email

We have 2 routers R1 and R2 with 4 links between them, we want to use BGP for exchanging routes between the two routers. We would like to establish a single BGP session between the 2 routers and not configure multiple BGP sessions using the physical IP addresses on the 2 links connecting the 2 routers.

lo — R1 === R2 — lo

We are hoping to use eBGP multi-hop feature. We have a requirement to load balance the traffic to the prefixes behind R1 using different weights that are assigned to the links.

router bgp 1
neighbor { <<< remote loopback-IP
multihop ttl 1;
update-source loopback0;
maximum-paths 2

static {
route next-hop ( |;

Since the recursive next hop is resolved via static route, there is no notion of load-balancing with un-equal weights. Is there a way to do UCMP with eBGP multi-hop for the example outlined above?

Posted by Alexis Dacquay
Answered on August 14, 2020 8:53 pm

Hi Sowmya,
Arista EOS supports BGP UCMP:

Some other UCMP-related features are:

UCMP - Auto-Adjust

UCMP - Append Interface Speed to Received Link-Bandwidth


Post your Answer

You must be logged in to post an answer.