05-10-2013 12:29 PM - edited 03-07-2019 01:18 PM
On one of our routers (running bgp and ospf), we are redistributing ospf to bgp. This router has a loopback interface which is advertised in ospf.
Router#sh ip route 10.22.0.24
Routing entry for 10.22.0.24/32
Known via "connected", distance 0, metric 0 (connected, via interface)
Redistributing via bgp 64999
Routing Descriptor Blocks:
* directly connected, via Loopback11
Route metric is 0, traffic share count is 1
I am confused about "Redistributing via bgp 64999" part.....Under router bgp, we are redist only ospf and static routes, but using route-maps like this:
redistribute static route-map STATIC2BGP
redistribute ospf 1 route-map OSPF2BGP
Obviously it won't match redistribute static because it is not static, but connected interface...And 10.22.0.24 does not appear in match statement in route-map OSPF2BGP, how is it still shown as "Redistributing via bgp 64999"?
Solved! Go to Solution.
05-14-2013 07:40 AM
Hi Kashish,
It appears that the current router is not the one redistributing the connected prefix into BGP. This prefix is received from one of the BGP peers. It might be worth looking at this peer to see if the redistribution filtering is adequate.
Regards
05-10-2013 03:01 PM
Do you have any null routes that might be used to encompass a range for loopbacks? I've commonly used null routes for loopback ranges just to ensure advertisement at an aggregation point.
05-11-2013 04:51 AM
Hi Kashish,
This prefix is owned by the ospf process. By redistributing ospf into bgp, this prefix would be redistributed in bgp as well. The "Redistributing via bgp 64999" does not take the filtering into account and appears as soon as redistribution is configured. So this message will show up even though this prefix is being filtered out by the OSPF2BGP route-map.
Regards
05-12-2013 11:04 AM
Hi Harold,
Thanks for replying.
Is the prefix actually getting redistributed in bgp here (even though not allowed in route map)?
Thanks.
05-12-2013 02:18 PM
Hi Kashish,
The prefix does not get redistributed if the route-map does not allow it.
Regards
05-12-2013 11:13 PM
That's where my confusion comes from.
Why does it still say:
"Redistributing via bgp 64999"?
05-13-2013 10:02 AM
Hi Kashish,
As I mentioned before, this message does not take into account whether the prefix is filtered or not but rather whether the protocol, the prefix was learned from, is redistributed or not.
Regards
05-13-2013 10:30 AM
Hi Harold,
I appreciate your response. I will explain my confusion (I may not have been clear before).
On some router A in our network, I see this in the output of "show ip bgp":
Router#sh ip bgp | i 10.22.0.24/32
*> 10.22.0.24/32 10.219.65.217 0 65000 64999 ?
Above output means that prefix 10.22.0.24/32 is actually redistributed in BGP on some router (say, router B in AS 64999)... Now router B has :
Router#sh ip route 10.22.0.24
Routing entry for 10.22.0.24/32
Known via "connected", distance 0, metric 0 (connected, via interface)
Redistributing via bgp 64999
Routing Descriptor Blocks:
* directly connected, via Loopback11
Route metric is 0, traffic share count is 1
and redistribution taking place via Route maps as I mentioned before:
redistribute static route-map STATIC2BGP
redistribute ospf 1 route-map OSPF2BGP
So from where is prefix 10.22.0.24/32 getting redist in BGP table when route-map is not even allowing it?
Thanks.
05-13-2013 11:31 AM
Hi Kashish,
Oh, I see. Can you please post route-map OSPF2BGP.
Regards
05-13-2013 12:04 PM
Harold,
Just sent you relevant config as a private message.
Thanks.
05-14-2013 01:03 AM
Hi Harold,
I hope you got the related configuration. Could you tell me the reason for my confusion?
Thanks.
05-14-2013 03:29 AM
Hi Kashish,
Could you please post the output of a "show ip bgp 10.22.0.24 255.255.255.255" from the router doing the redistribution.
Regards
05-14-2013 03:52 AM
Just sent you that.
05-14-2013 07:40 AM
Hi Kashish,
It appears that the current router is not the one redistributing the connected prefix into BGP. This prefix is received from one of the BGP peers. It might be worth looking at this peer to see if the redistribution filtering is adequate.
Regards
05-15-2013 05:25 AM
Thanks...That was it!
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide