hi,all:
i would like to ask for you thoughts on the following scenario.
CE1---(ebgp)---PE1---PE2----(ebgp)---CE2
I have a backdoor link between CE1/2 and i'm running ospf for loopbacks and backdoor link only.
I just want to share my thoughts on this and see what you think, always from design point of view (or best answer for exam). to me, this scenario only calls for redistribution from bgp---> ospf only, plus two ebgp network statements for loopbacks CE1/CE2 on both CEs out to the PEs.
since i did not configure mutual redistribution bgp<--->ospf, there is no way a loop can form. if the backdoor link breaks each CE will advertise its own loopback only, because the other loopback will be lost from igp. traffic going to other sites will always prefer the vpn because of bgp admin distance and will prefer backdoor link for other CE's loopback only. (you guys think using the backdoor link for CE1<-->CE2 communications would be frowned upon at the lab exam?)
now for some reason i was thinking of SOO on the ebgp sessions, and here some confusion arises as to wether SOO propagates upwards to network core and ALSO downward to CE. from what i can see bgp SOO does not go to CE, but only toward network core. should i use SOO in this scenario to avoid CE2 relearning from BGP the loopback from CE1 it already learns from CE1 via ospf?
The only thing that worries me here is if i use same SOO, like i think i'm supposed to, then if backdoor link breaks, CE2 would not learn CE1 loopback through BGP(PE2).
thoughts on this scenario?
thanks in advance!
c.