BGP to OSPF redistribution, BGP routes show in IP route table

[aacole]

I have recently set up a BGP to OSPF redistribution, all is working OK. But I cannot explain the following: If I show ip route I see the redistributed routes as BGP routes, I would have expected to see these as OSPF routes which have a better Admin distance.

The router is correctly advertising the routes learnt from BGP, but the sh ip ro isnt what I expected.

[steve.barlow]

Can you post the relevant config and show outputs?

Steve

[aacole]

Steve,

Eventually got back to site, here is the config from the 3660 with some out the output from the route table:

3660 shows BGP learnt routes as BGP.

router ospf 1

log-adjacency-changes

redistribute static metric 100 metric-type 1 subnets

redistribute bgp 10 metric 1 subnets

network 0.0.0.0 255.255.255.255 area 0

!

router bgp 10

no synchronization

bgp redistribute-internal

bgp log-neighbor-changes

neighbor 192.168.1.129 remote-as 10

no auto-summary

sh ip ro

51.0.0.0/8 is variably subnetted, 50 subnets, 7 masks

B 51.65.235.152/30 [200/10000] via 51.65.229.161, 2d01h

B 51.65.235.156/30 [200/10000] via 51.65.229.161, 2d01h

B 51.65.235.144/30 [200/10000] via 51.65.229.161, 2d01h

B 51.65.235.148/30 [200/10000] via 51.65.229.161, 2d01h

next is the confg from a 4500 switch with RSM, this shows routes as OSPF E2.

4503 shows the routes learnt from BGP as OSPF

router ospf 1

log-adjacency-changes

redistribute static metric 100 metric-type 1 subnets

redistribute bgp 10 metric-type 2 subnets

network 0.0.0.0 255.255.255.255 area 0

!

router bgp 10

no synchronization

bgp redistribute-internal

bgp log-neighbor-changes

neighbor 192.168.1.1 remote-as 10

no auto-summary

sh ip ro

51.0.0.0/8 is variably subnetted, 51 subnets, 7 masks

O E2 51.65.235.152/30 [110/1] via 10.5.224.21, 01:17:56, Vlan100

O E2 51.65.235.156/30 [110/1] via 10.5.224.21, 01:17:56, Vlan100

O E2 51.65.235.144/30 [110/1] via 10.5.224.21, 01:17:56, Vlan100

O E2 51.65.235.148/30 [110/1] via 10.5.224.21, 01:17:56, Vlan100

O E2 51.65.235.136/30 [110/1] via 10.5.224.21, 01:17:56, Vlan100

O E2 51.65.224.128/26 [110/1] via 10.5.224.21, 01:17:56, Vlan100

Any thoughts?

[deilert]

are the routes internal or external BGP . External BGP has a distance of 20 . Internal has a distance of 200 .

[ERIK LAWAETZ]

BGP routes have different Administrative Distance (AD) depending on whether they're external (20) or internal (200).

OSPF has an AD of 110.

So if you're redistributing eBGP routes into OSPF, then they'll still show up in your routing table as BGP routes, since their AD is 20.

[aacole]

The routes I am inporting are iBGP, and show in the IP route table with an AD of 200, so I wouldn't expect to see them.

[deilert]

If you do a sh ip o dat external n.n.n.n m.m.m.m

do they show up in the ospf database ?

You may also want to try a 'clear ip o redistribution'

[a.diot]

hi

I've got exactly the same pb,i tried to redistrib ibgp to ospf with a 2610 and a 2611

two dif ios , same results my routes are ibgp instead of ospf and don't appear in

database,so i tried to replace ospf with eigrp , same behavor route is advertised

but receiver don't include them?

i' ve posted a topic in this forum ,please let me know if you have an answer

Regards

Alain

[r-hermoni]

Hi ,

Can you send please the sh ip bgp output.

(I'm suspecting on the Origin Attribute)

Thx

Roi

[kcollin]

x