[ ] ------Switch1---------- [Router1]
[ B ] I
[ S ] I
[ C ] -----Switch2---------- [Router2]
Primary Board is active and secondary board is standby mode .Primary Board of BSC is connected with Router 1 through Swicth1 and Secondary Board of BSC is connected with Router2 through switch2.Routing for BSC is done to towards switch 1 on Router1 and towards switch 2 on Router 2. If Board of BSC Board got switch over due to any reason. Primary routing of BSC is still towards Switch 1 on router1 because port which is conntected between router and switch is not going down. Routing for BSC Board IP address will be remain towards switch1 on router 1. Both Boards are not having same IP address,
x.x.x.x/29 pool is reserve for BSC lan. x.x.x.1/29 is given to primary Board and x.x.x.2/29 is given to seconadry Board.
To handle this issue, we have implemented the BFD between Router and BSC. After implementing BFD , if Primary Board got switchover. it will make the BSC routing change from primary path to backup path by making port (which is connected between router 1 and switch 1) down.
Below is BED Configuration at the router end:-
bfd to_BSC bind peer-ip x.x.x.x (BSC LAN IP address)
discriminator local 807
discriminator remote 708
At the time analyising this problem, we found that BSC routing still there on the Router 1 towards Switch 1after BSC board got switchover due to any reason because port is not going down. Router will still keep forwarding the data to Switch 1 only. Result BSC communication through Switch 1 is failure which is not primary anymore after switchover.
BFD should be implementing where port is not physically going down whenever BSC baord switch over is happening.