BGP peerings

[visitor68]

Hi - basic question, but I am rusty...can one have two physical BGP peerings between two routers? I know one can LAG them up and use a loopback address, but what if one wanted to maintain two separate physical peering links?

[Harold Ritter · Accepted solution]

Hi,

Yes, it is certainly possible to have multiple BGP sessions between two routers. The drawback is that you will receive several paths (one per session), which will consume more memory. The best way to use multiple physical interfaces between the 2 routers would be to have one BGP session between the loopback interfaces and have static routes to the neighbor loopback via the multiple interfaces, which will provide load balancing.

Regards,

[Martin L · Accepted solution]

yes, but not recommended ; ususally we have 2 links between BGP routers and 1 sessions established from loopback to loopback.  To make sure bgp session is up , use update source loopback x and time to live is 2 hops away (eighbor ebgp-multihop command ) . 

[visitor68]

Thank you, gentlemen.