ebgp multihop question

[tarik sayel]

Hi all,

I need to know if is it possible to use ebgp multihop on a CE with two links, one link is connected to PE1 and the other link is connected to PE2 (one CE with 2 links to two different PEs).

thanks

[John Blakley]

Tarik,

Ebgp multihop is for when you have a peer that's more than 1 hop away. By default, bgp sets the ttl to 1. It doesn't sound like you need multihop configured if you have a neighbor that's only 1 hop away.

Hth,

John

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[tarik sayel]

Hi,

thanks Blakley,

i want to mean multiphat, sorry for that

i want to assure the load sharing between this two links.

BR

[John Blakley · Accepted solution]

Yes...it will support it as long as you have identical routes in the bgp table. You can enable "maximum-paths" under bgp:

router bgp 1

maximum-paths 2

You may also need to enable multipath relax:

bgp bestpath as-path multipath-relax

The idea is that if you are learning 2 identical routes from the same AS, then you'll need to enable maximum-paths only. By default, BGP doesn't load balance and only puts 1 route in the routing table. If you are learning 2 identical routes from 2 different ASes, you'll need to enable the second command.

HTH,

John

[tarik sayel]

Thanks for your help Blakley, it's now clear