BGP reflector and load balance.

flyjunli · ‎08-19-2009

i know Route reflector only reflect one single best path to it's clients, is there any method to make route reflector to reflect multiple equal best path to it's client? such as from EBGP.

thank you!

tom

Giuseppe Larosa · ‎08-19-2009

Hello Tom,

if the routes are placed in a VRF and the two PE nodes use a different Route Distinguisher you can overcome this limit.

Client PE will need also the

maximum-paths eibgp n

inside VRF address family in BGP router process.

In global routing table the RRS will compare the two routes and will make a choice.

To propagate two different routes to clients:

use two different route reflector servers with RRS1 that prefers path1 and RRS2 that prefers path2 (may be for a local selective weight setting inbound on the RRS2).

But this approach may not be practical.

Hope to help

Giuseppe

flyjunli · ‎08-20-2009

Hi Giuseppe,

Thank you!

is there any easy way to implement this. I think choose best path is a natural algrithm on RRS, I can't modify this behaviour at all,But why,because BGP is a loop free protocol.

i think another solution, i divide two RRS to two different group. each group has it's clients including one router has one EBGP path. therefore two EBGP path(to the same destination) seperated into two different group.

but we just have two RRS,if we seperate two RRS,we only have one RRS in each group. there has redundancy problem.

it seems it is not easy to find a solution.

thank you!

Tom