From: Alexander Arsenyev (GU/ETL) (alexander.arsenyev@ericsson.com)
Date: Wed Jul 28 2004 - 06:45:51 GMT-3
Hello,
You are right on Cisco/Juniper behavioral differences below. FYI, to make Juniper box announce "ineligible" routes
use command "advertise-inactive". Note that for this command to work the route must be coming from BGP AND IGP (OSPF in Your case).
I think this difference relies on the meaning of word "route". It seems to me that Cisco box understands "route" as prefix/netmask combination (without taking next hop, etc into consideration) whereas Juniper box sees "route" as prefix/netmask/next-hop & possibly other attributes' combination. That's why sometimes number of routes in "show route" output on Juniper box is much greater than number of prefixes.
HTH,
Cheers
Alex
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
jongsoo.kim@intelsat.com
Sent: 27 July 2004 21:08
To: ccielab@groupstudy.com
Subject: Different behavior on BGP announcement between cisco and
Juniper
I found some different behavior between cisco and Juniper when a BGP route accidently announced via OPSF. Basically, Juniper stop announcing route via BGP while cisco seems to announce BGP and OSPF. I am using cisco as access and juniper as core.
I need validation on the below statment, which was my conclusion on this problem.
It seems that Cisco announce BGP routes to iBGP peer as long as it shows in BGP table( show ip bgp) as "eligible" route, regardless of appearance on routing table. It means if the router learns the same route via OSPF, it will still announce the route via BGP.
But Juniper only announces BGP routes to iBGP peer only which show as active route(best route) in the local forwarding table. It means if the router learns the same route via OSPF, it will not announce the route via BGP as the route in forwarding table only shows as OSPF active route not BGP.
Thanks
Jongsoo
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