Connecting OSPF to eBGP

[Ardhiannash]

Hi,

i have some problem with connecting OSPF to eBGP

im using OSPF to connect the VLAN 10 and 20 to R1 but im unable to ping to the other AS. 

after i configure the eBGP, R1 able to ping 192.168.30.1 on R3 but unable to ping 192.168.30.2 on R4.

here's my configuration.

R2

router ospf 10

network 10.10.11.0 0.0.0.255 area 0

network 10.10.12.0 0.0.0.255 area 0

network 192.168.20.0 0.0.0.3 area 0

R1

router ospf 10

network 192.168.20.0 0.0.0.3 area 0

router bgp 100

neighbor 192.168.10.2 remote-as 200

network 192.168.10.0 mask 255.255.255.252

neighbor 192.168.10.2 next-hop-self

R3

Router ospf 10

network 192.168.30.0 0.0.0.3 area 0

router bgp 200

neighbor 192.168.10.1 remote-as 100

network 192.168.10.0 mask 255.255.255.252

neighbor 192.168.10.1 next-hop-self

since GNS3 doesn't support inter-vlan routing, im using OSPF. When i look at the routing table

on R1 it's said that network 192.168.30.0 have no Next-hop address (direct)

does anyone have solution for this? im new at this and cant figure it out on my own.

[Seb Rupik]

Hi there,

You need to redistribute the OSPF routes in the BGP process and vice versa. This will advertise the internal routes to the BGP peer.

At its simplest, this should work:

!! R2
!
router ospf 10
  redistribute bgp 100
router bgp 100
   redistribute ospf 10
!

!! R3
!
router ospf 20
  redistribute bgp 200
router bgp 200
   refistribute ospf 20
!

cheers,

Seb.

[Ardhiannash]

Hi, thanks for your reply

i tried to redistribute the OSPF and it said:

R3(config)#router ospf 20
R3(config-router)#redistribute bgp 200
% Only classful networks will be redistributed
R3(config-router)#

and im still unable to ping from R1 to PC4.

im using OSPF and eBGP on R1 and R3.

i check the OSPF and there is nothing wrong with it.

R1 able to ping PC2 & PC1

R3 able to ping PC3 & PC4.

do you have any other suggestion?

[Seb Rupik · Accepted solution]

Try:

!! R2
!
router ospf 10
  redistribute bgp 100 subnets
!

!! R3
!
router ospf 20
  redistribute bgp 200 subnets
!

Then share the output of sh ip route from R2 and R3.

[Ardhiannash]

Thanks you for the solution, its work perfectly.