[c-nsp] BGP load-sharing *and* redundancy across 2 routers

Robert Gutierrez rmg at conviva.com
Mon Oct 20 16:53:31 EDT 2008


Hi all.  I have a typical BGP loopback setup to my ISP.  4 links across 2
routers.  2 links on each router. Easy -- no problemo.

Now, how can I get loopback address redundancy?  I'm currently using
Router "A" as my loopback address, with an iBGP to Router "B", and
multihop and maximum-paths set up.  So Router "A" knows about all 4 links
outbound.

Now, if I lose Router "A" (crash, power-off, etc), I want Router "B" to
pick up the peering of it's 2 links, and bring the BGP session back up.
The only way that I can figure out is (1) Make the loopback address an
HSRP across both routers (is that even possible or been done?), or (2)
Just bring up sessions on both routers using the same Loopback address.

I guess the "right" way is to use 2 different loopback addresses, one for
each router, and bring up peers for both, and use MEDs or their community
map to make them pref one way or another across each loopback peer (with
myself using local-pref).  Do you know of any Tier-1's that let you do
this?

Thanks in advance!

   Rob Gutierrez / Conviva Inc.



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