08-11-2007 01:34 AM - edited 03-05-2019 05:50 PM
hi everyone, i had a question regarding bgp.
Suppose i have 2 routers peering with an ISP ( whether same ISP or 2 different ISP ) lets name these routers RA and RB. i want RB to make a peering session with its ISP if and only if RA fails its bgp session, now u can also assume that RA fails completely or just loses its bgp connection, in either case i want RB to start its own bgp session, so i want to make RB backup of RA in terms of BGP.
how can it be possible
08-12-2007 09:10 PM
yes. that is commonly used. you can have backup line via BGP or have 2 paths likely loadbalancing.
08-13-2007 12:47 AM
can u kindly tell me that how its possible ? what configuration i have to do ???
08-13-2007 01:09 AM
The only way i could think of achieving this is by configuring BGP over loopbacks and making sure that it is reachable only when your primary links come up.
Narayan
09-20-2007 08:48 PM
that is very simple. you just command maximum-path 2. but please make sure all of BGP best path selection procedure.
router bgp 10
neighbor x.x.x.x remote-as xxxx
maximum-paths 2
end
09-20-2007 11:55 PM
hello
i don't know exactly why you want to to this but you should do like this :
RA <=EBGP=> ISP
RB <=EBGP=> ISP
AND
RA <=IBGP=> RB
then RA set localpref150 on incoming routes,
RB do as path prepend on outgoing routes...
it's more clean than 'conditionnal peering'
Etienne
09-22-2007 07:23 PM
Dear etienne,
I guess that he wants to have 2 paths on the same router. this means link redundency vis bgp not router redundency.
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