If RR is receiving same prefix (prefix A) from two routers (Router B and C) with same AS path then which route (with path B or c) will get advertised to route reflector client.
I thought that RR should propagate most stable route to RR client but it was propagating route with best router id.
Can someone help me to understand..
there is nothing in the BGP best path algorithm that specifies a 'stable' path...how do you define a stable vs an unstable path ?
The original question seems to imply that the path selection for RR is different from regular BGP path selection. As far as I know there is not anything different in path selection for RR. See this link for some details about path selection.
I observing in my environment that we are learning route 10.10.10.0/24 on RR from router 1 (Router id 192.168.10.1 ) and router 2 (router id 192.168.10.2 ) with same AS path.
RR is propagating route received from router 1 due to lowest router id but if if due to some reason if router 1 is not receiving (from neighbor) route and sending to RR , the RR is refreshing the route in RR client i.e route from Router 2. But when router 1 again learn the roue from neighbor and advertised to RR , RR send Router 1 route to RR client.
My question is if route learning from Router 2 in RR routing table for more time period then why RR send R1 router route to RR client
This is correct/expected behavior, BGP runs a scanner process that checks for next-hop and best-routes. As soon as a better route is received, RR will announce it further to RR-clients. This has nothing to do with the age of the route in RR routing table. RR will only announce the best BGP path to RR-clients. Since R1 is provides RR a better route with lowest router ID, it marks it as the best path and then propagates it to other RR-clients.
Hope this all make sense now.
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