internal routes get lost

[dong-lee]

Hello,

Our internal routes flushed out of routing table time to time for some season. Could anyone please shed a light to this problem?

We have four routers. Router1, router2 and router3 are fully meshed. Router3 and router4 are route reflectors as shown on diagram below.

Router1-------Router2

- -

- -

Router3(RR)-------------Router4(RR)

We are running iBGP with all routers, and below is what we are seeing from router4,

ala-oc12-rtr#sh ip route 192.168.32.1

Routing entry for 192.168.32.0/19, supernet

Known via "bgp 66055", distance 200, metric 0, type internal

Last update from 10.125.28.1 00:00:31 ago

Routing Descriptor Blocks:

* 10.125.28.1, from 10.125.28.101, 00:00:31 ago

Route metric is 0, traffic share count is 1

AS Hops 0

ala-oc12-rtr#sh ip bgp 192.168.32.1

BGP routing table entry for 192.168.32.0/19, version 1214376

Paths: (1 available, best #1, table Default-IP-Routing-Table)

Flag: 0x208

Advertised to non peer-group peers:

10.123.21.193

Local

10.125.28.1 from 10.125.28.101 (64.176.100.50)

Origin IGP, metric 0, localpref 100, valid, internal, best

Originator: 64.176.100.50, Cluster list: 64.176.100.50

ala-oc12-rtr#sho ip route 192.168.32.1

% Network not in table

ala-oc12-rtr#sho ip bgp 192.168.32.1

BGP routing table entry for 0.0.0.0/0, version 874889

Paths: (1 available, best #1, table Default-IP-Routing-Table)

Not advertised to any peer

209

10.123.21.193 from 10.123.21.193 (205.171.3.201)

Origin IGP, metric 0, localpref 100, valid, external, best

Thank you in advance....

[Harold Ritter]

192.168.32.0/19 is definitely flapping. It could be due to the BGP session flapping or the originator advertising and withdrawing the prefix.

Is the bgp session itself stable? Could you provide a "sh ip bgp 10.125.28.101". Just curious, is this real output from the RR "Known via "bgp 66055"" ;o)

Thanks,

[dong-lee]

Hi,

Thanks for replay.

I was missing static route pointing next hop, and it is fixed now.

Thanks again.