BFD CONFIGURATION FOR eBGP Multihop on CRS

[Amauri Soto Rodriguez]

Hi All,

One of my customers wants to implement BFD on an eBGP multihop session between an CRS-1 against a Juniper router, I was checking some information about it but some of the documents I found were related to IOS or specifically to ASR9K platforms.

Has anyone of you implemented previously this kind of config on CRS's, does it have to be configured something on line cards in order the BFD packets can go and come throught the CRS's?

Highly appreciated your thoughts.

[xthuijs]

yup that can be done, some extra config is required.

on the endpoint node, we need to configure multihop bfd location to direct an LC to be owner of the bfd session and support multihop bfd.

a config guide is here for that:

http://www.cisco.com/c/en/us/td/docs/routers/crs/software/crs_r4-3/routing/configuration/guide/b_routing_cg43xcrs/b_routing_cg43xcrs_chapter_011.html

also I would recommend to make sure proper qos on the intermediate nodes is available to provide the right priority to the bfd (echo) packets as they go through that node.

also be careful wtih bfd echo and urpf, since bfd echo packets I am sending to you have me as destination and you as source, so effectively would fail a uprf check.

cheers

xander