From: Todd, Douglas M. (DTODD@PARTNERS.ORG)
Date: Sat Apr 28 2007 - 10:27:59 ART
I believe you will get a rib failure w/the EGP routing table when there is a
more preferred IGP route in the FIB already. As long as the criteria for
advertising the route is met, the router should advertise the route to the
neighbor. Best thing is to try it out and see if you get what you want? Remove
the igp route which is causing the failure and you will have the bgp route
installed in the table. with a rib failure you should still see the route
advertised via bgp to other neighbors.
DMT
-----Original Message-----
From: nobody@groupstudy.com on behalf of backbone systems
Sent: Sat 4/28/2007 1:56 AM
To: Cisco certification
Subject: RIB failure Question
Dear GS,
I have question regarding RIB failure
"If a route is appearing in BGP table as "r"' can that route be advertised
to any EBGP or iBGP peer?"
ok the scenario is that on R1 sync is enabled and i am learning
5.5.5.5route from an IBGP peer .I am also redistributing this route in
OSPF as sysn is enabled and i must learn the route from IGP too.The route
from ospf is installed in routing table b/c of the
better admin distance.The route from the IBGP peer is appearing as RIB
failure b/c a better route is there in routing table .
Now can this "r" route be advertised to an any BGP peer????
To get a clear pic,if some body has done IE advanced technolgy labs .In the
BGP section there is a scenario named "IBGP Syncronization".
In this lab the route 5.5.5.5 is appearing as "r" in BGP table but it is
still being advertised to an EBGP peer ?Am i missing something?
Can somebody clarify this.
Secondly in the sh ip bgp 5.5.5.5 out put below what is meant by "table
Default-IP-Routing" because when i tried to this lab the only thing
that was missing from my output was this.
R1#show ip bgp
BGP table version is 8, local router ID is 14.0.0.1
Status codes: s suppressed, d damped, h history, * valid, >
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf
Weight Path
*> 4.4.4.4/32 14.0.0.4 0
0 4 i
r>i5.5.5.5/32 25.0.0.5 0 100
0 5 i
R1#show ip bgp 5.5.5.5
BGP routing table entry for 5.5.5.5/32, version 8
Paths: (1 available, best #1, table Default-IP-Routing-
Table, RIB-failure(17))
Advertised to non peer-group peers:
14.0.0.4
5
25.0.0.5 (metric 855) from 23.0.0.2 (25.0.0.2)
Origin IGP, metric 0, localpref 100, valid, internal,
synchronized, best
R4#show ip route 5.5.5.5
Routing entry for 5.5.5.5/32
Known via "bgp 4", distance 20, metric 0
Tag 1, type external
Last update from 14.0.0.14.0.0.1 00:00:57 ago
Routing Descriptor Blocks:
* 14.0.0.1, from 14.0.0.1, 00:00:57 ago
Route metric is 0, traffic share count is 1
regards
backbone
This archive was generated by hypermail 2.1.4 : Tue May 01 2007 - 08:28:38 ART