RE: bgp problem

From: Bob Sinclair <bob_at_bobsinclair.net>
Date: Mon, 30 Aug 2010 09:51:49 -0400

Hello Mustafa,

 

RIB failure means that BGP cannot put the route into the forwarding table.
The most common reason is because there is a matching route from another
source with a lower administrative distance. RIB failure should not, in
itself, prevent BGP from advertising the route to peers.

 

You are correct that a route must be chosen "best" to be used or advertised,
but it looks to me from your output that all of these routes have been
chosen best:

 

> r>i28.119.16.0/24 54.9.3.254 0 100 0 54 i

 

Note the best indicator ">" in your output. Try show ip bgp 28.119.16.0,
for example, and you will see you have a "best".

 

HTH,

 

Bob Sinclair CCIE 10427 CCSI 30427

CIERS2 Online Instructor

www.tinyurl.com/ciers2online

 

> -----Original Message-----

> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of

> Mustafa Yadav

> Sent: Monday, August 30, 2010 9:42 AM

> To: Cisco certification

> Subject: bgp problem

>

> Hi all,

>

> I had a strange situation.In R1 some bgp prefixes shown as rip failure

> but

> somehow they have been advertised to R5 .In r5 in routing table they

> shown

> as normal routes came from bgp table.I will go fro a troobleshooting

> but

> before I want to knoe .Is it possible for a prefix which has rib

> failure to

> be advertised to a ebgp neighbor?

>

> As far as I know for a prefix to be advertised it has to be chosen best

> and

> go to routing table.Am I wrong?

>

>

>

> Rack9R1#sh ip bgp neighbors 136.9.16.5 ad

> Rack9R1#sh ip bgp neighbors 136.9.16.5 advertised-routes

> % No such neighbor or address family

> Rack9R1#sh ip bgp neighbors 136.9.15.5 advertised-routes

> BGP table version is 1184, local router ID is 150.9.1.1

> 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

> r>i28.119.16.0/24 54.9.3.254 0 100 0 54 i

> r>i28.119.17.0/24 54.9.3.254 0 100 0 54 i

> r>i54.9.3.0/24 136.9.136.6 0 100 0 i

> r>i112.0.0.0 54.9.3.254 0 100 0 54 50 60 i

> r>i113.0.0.0 54.9.3.254 0 100 0 54 50 60 i

> r>i114.0.0.0 54.9.3.254 0 100 0 54 i

> r>i115.0.0.0 54.9.3.254 0 100 0 54 i

> r>i116.0.0.0 54.9.3.254 0 100 0 54 i

> r>i117.0.0.0 54.9.3.254 0 100 0 54 i

> r>i118.0.0.0 54.9.3.254 0 100 0 54 i

> r>i119.0.0.0 54.9.3.254 0 100 0 54 i

> Total number of prefixes 11

> Rack9R1#sh ip bg

> Rack9R1#sh ip bgp

> BGP table version is 1184, local router ID is 150.9.1.1

> 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

> r>i28.119.16.0/24 54.9.3.254 0 100 0 54 i

> r>i28.119.17.0/24 54.9.3.254 0 100 0 54 i

> r>i54.9.3.0/24 136.9.136.6 0 100 0 i

> r>i112.0.0.0 54.9.3.254 0 100 0 54 50 60 i

> r>i113.0.0.0 54.9.3.254 0 100 0 54 50 60 i

> r>i114.0.0.0 54.9.3.254 0 100 0 54 i

> r>i115.0.0.0 54.9.3.254 0 100 0 54 i

> r>i116.0.0.0 54.9.3.254 0 100 0 54 i

> r>i117.0.0.0 54.9.3.254 0 100 0 54 i

> r>i118.0.0.0 54.9.3.254 0 100 0 54 i

> r>i119.0.0.0 54.9.3.254 0 100 0 54 i

> *> 205.90.31.0 136.9.15.5 0 200 254 ?

> *> 220.20.3.0 136.9.15.5 0 200 254 ?

> *> 222.22.2.0 136.9.15.5 0 200 254 ?

> Rack9R1#

> RSRack9AS>5

> [Resuming connection 5 to R5 ... ]

> Aug 30 06:35:34.351: %OSPF-5-ADJCHG: Process 1, Nbr 150.9.4.4 on Seria

> Rack9R5#sh ip bg

> Rack9R5#sh ip bgp

> BGP table version is 15, local router ID is 150.9.5.5

> 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

> * 28.119.16.0/24 136.9.245.2 0 300 100 54

> i

> *> 136.9.15.1 0 100 54 i

> * 28.119.17.0/24 136.9.245.2 0 300 100 54

> i

> *> 136.9.15.1 0 100 54 i

> * 54.9.3.0/24 136.9.245.2 0 300 100 i

> *> 136.9.15.1 0 100 i

> * 112.0.0.0 136.9.245.2 0 300 100 54

> 50

> 60 i

> *> 136.9.15.1 0 100 54 50

> 60 i

> * 113.0.0.0 136.9.245.2 0 300 100 54

> 50

> 60 i

> *> 136.9.15.1 0 100 54 50

> 60 i

> * 114.0.0.0 136.9.245.2 0 300 100 54

> i

> *> 136.9.15.1 0 100 54 i

> * 115.0.0.0 136.9.245.2 0 300 100 54

> i

> *> 136.9.15.1 0 100 54 i

> * 116.0.0.0 136.9.245.2 0 300 100 54

> i

> *> 136.9.15.1 0 100 54 i

> * 117.0.0.0 136.9.245.2 0 300 100 54

> i

> Network Next Hop Metric LocPrf Weight Path

> *> 136.9.15.1 0 100 54 i

> * 118.0.0.0 136.9.245.2 0 300 100 54

> i

> *> 136.9.15.1 0 100 54 i

> * 119.0.0.0 136.9.245.2 0 300 100 54

> i

> *> 136.9.15.1 0 100 54 i

> *> 205.90.31.0 192.10.9.254 0 0 254 ?

> *> 220.20.3.0 192.10.9.254 0 0 254 ?

> *> 222.22.2.0 192.10.9.254 0 0 254 ?

> Rack9R5#ship ro

> Rack9R5#sh ip ro

> Rack9R5#sh ip route bg

> Rack9R5#sh ip route bgp

> B 119.0.0.0/8 [20/0] via 136.9.15.1, 00:04:15

> B 118.0.0.0/8 [20/0] via 136.9.15.1, 00:04:15

> B 222.22.2.0/24 [20/0] via 192.10.9.254, 00:04:15

> B 117.0.0.0/8 [20/0] via 136.9.15.1, 00:04:15

> B 220.20.3.0/24 [20/0] via 192.10.9.254, 00:04:15

> B 116.0.0.0/8 [20/0] via 136.9.15.1, 00:04:15

> B 115.0.0.0/8 [20/0] via 136.9.15.1, 00:04:15

> B 114.0.0.0/8 [20/0] via 136.9.15.1, 00:04:15

> 54.0.0.0/24 is subnetted, 1 subnets

> B 54.9.3.0 [20/0] via 136.9.15.1, 00:04:15

> B 113.0.0.0/8 [20/0] via 136.9.15.1, 00:04:15

> B 112.0.0.0/8 [20/0] via 136.9.15.1, 00:04:15

> 28.0.0.0/24 is subnetted, 2 subnets

> B 28.119.17.0 [20/0] via 136.9.15.1, 00:04:15

> B 28.119.16.0 [20/0] via 136.9.15.1, 00:04:15

> B 205.90.31.0/24 [20/0] via 192.10.9.254, 00:04:15

> Rack9R5

>

>

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Received on Mon Aug 30 2010 - 09:51:49 ART

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