BGP ,OSPF with default route

[Rashmiranjan jena]

Hi ,

My branch office is getting internet through Head office & connected through Lease line and ospf is running. one static route 0.0.0.0 id defiend towards HO.

Now one extra link is added with our wan for redundancy MPLS link & EBGP is running .

My question is how to configure ospf route(my internal network) to bgp & default route (for internet) for connectivity ?

Please help with examples .

Thank You

[Pawan Raut]

Could you please explain what exactly you would like to achieve.

do you want the wan link (Leased line and MPLS) as active standby. then which would be Primary you want?

[Rashmiranjan jena]

Hi Sir,

My branch router connected with HO with lease line & OSPF is configured for wan  & lan network.

i have added one more wan mpls link with bgp protocol . both link will run simultaneously if any link is goes down other should work .if i redistribute ospf to bgp then it may loop occurs in bgp link. 

in bgp i want configure ospf route & internet traffics should allow over mpls bgp from branch router to HO access.

My branch router also getting inter from HO.

[Pawan Raut]

To avoid loop you should configured route-map allowing only LAN subnets of branch to redistribute in BGP.

Create prefix-list allowing all LAN subnets

ip prefix-list LAN-subnet seq 5 permit x.x.x.x

i

route-map OSPF-TO-BGP permit 10

match ip prefix-list  LAN-subnet

!

router bgp xxxx.

redistribute ospf xxx route-map OSPF-TO-BGP

!

router ospf xxx

default-information originate

!

[Rashmiranjan jena]

Hi Sir,

If my lease line ospf (old link) link will goes down then can my branch router will get internet through mpls bgp link 

any command for internet needs add or not 

Please check my attached previous post diagram 

[Pawan Raut · Accepted solution]

For internet you need default route. I am assuming you will get default route from MPLS as well so leased  line will go down defualt route from MPLS BGp will get inject into LAN by this command which I was already added in your config.

router ospf xxx

default-information originate

!

Also if your are connecting Lased line and MPLS on same router then router will choose MPLS as Primary path as eBGP preferred then ospf . So you ave to change BGP routes AD so that ospf will get prefer than BGP. Use below config for Leased line as Primary and MLPS as secondary.

router bgp xxx

distance bgp 200 200 200

!

[Rashmiranjan jena]

Hi sir,

My Ho router is connected with internet & my branch router is getting internet through HO router So in witch router ,i needs put that command "default-information originate" or in both router

[Pawan Raut]

Branch router