Redundancy with OSPF

[a91249124]

Hi Guys

Please find the attached topology

I have two router names R1 and R2

I am running OSPF b/w SW1 and R1

OSPF b/w SW2 and R2

iBGP b/w R1 and R2

HSRP b/w R1 and R2 ---- Firewall points to HSRP VIP and redundancy is achieved

In case Router R1 fails , SW1 losses OSPF relationship with R1 and It wont be able to reach firewall

In case Router R2 fails , SW2 losses OSPF relationship with R2 and it wont be able to reach firewall

Can you please provide me with a solution so that if R1 fails SW1 will still be able to reach firewall via R2

Thanks

[a91249124]

[paul driver · Accepted solution]

Hello

Create an additional ospf adjacency between SW1& SW2.

res

Paul

Please don't forget to rate any posts that have been helpful.

Thanks.

[antonio.guirado]

Hello,

I agree pdriver. You need a alternative path. My recommendation is create a VLAN that connect R1 (f0/0), R2 (f1/0), sw1 (fe0/3 and f0/0), sw (fa0/0 and f0/2). If you want you can propage it to intermediate switch if you have STP enable. Why this topology?. Beacause OSPF is specially designed to work in a LAN topology electing a Designated router (DR) and a Back DR( BDR). Relationships are established bettween DR router and the others (also BDR and the others) and multicast protocol is used. It consumes less BW and CPU process in routers. You can use (opsf priority command) R1 and R2 as

DR and BDR. All devices must be in area 0.

Be careful with iBGP (administrative distance 200) and OSPF (administrative distance 110).

Think if you want to also enable OSPF between R1 and R2.

Regards.

[a91249124]

Hi there Thanks for your reply

aim is to run ospf b/w router and switches then redistribute in bgp and then send the bgp routes to remote site via mpls

[a91249124]

Another Quick one How can I assure that all traffic utilizes R1 only from both the switches. R2 just sits there as standby

Thanks

[antonio.guirado · Accepted solution]

Hello,

use "ip ospf cost 100" command in fe0/2 of switch 2. So the prefered path in switch 2 will be switch1.

Regards

[a91249124]

Hi Antonio,

                Sub interface fa0/2 is not accepting ip ospf command

[a91249124]

All done thanks Put it under vlan interface