BGP next-hop

Jeff Saxe jsaxe at briworks.com
Thu Sep 30 06:13:51 CDT 2010


Yes, I believe the command is "show ip bgp rib-failure". This shows routes that are in the BGP table, theoretically eligible to be used as actual traffic-forwarding routes, but are failing to be inserted into the Routing Information Base (RIB) for one reason or another. I don't have a lab router handy to lab it up, and of course on my normal production router it comes up empty (lists column headers, but no routes) because I don't have any edge cases on there right now. But I think this is what you want.

-- Jeff Saxe
Network Engineer, Blue Ridge InternetWorks
Charlottesville, VA


________________________________________
From: Heath Jones [hj1980 at gmail.com]
Sent: Thursday, September 30, 2010 5:49 AM
To: nanog at nanog.org
Subject: BGP next-hop

Hi all,

Is there an easy way to see which iBGP routes are not being selected
due to next-hop not being in IGP?

Before and after IGP route added shown below, note both are marked as valid..

-- BEFORE IGP--
AS5000_LA#show ip bgp
BGP table version is 5, local router ID is 10.0.0.5
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
             r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

  Network          Next Hop            Metric LocPrf Weight Path
* i100.10.0.0/16    10.0.0.10                0    100      0 2000 3000 ?
*>                  10.0.0.6                               0 1000 3000 3000 ?

-- AFTER IGP--
AS5000_LA#show ip bgp
BGP table version is 6, local router ID is 10.0.0.5
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
             r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

  Network          Next Hop            Metric LocPrf Weight Path
*>i100.10.0.0/16    10.0.0.10                0    100      0 2000 3000 ?
*                   10.0.0.6                               0 1000 3000 3000 ?


Cheers
Heath

ps. I've posted this to cisco-nsp also (a day ago) - so apologies in
advance if you are on both and seeing it twice.





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