Thanks for reply milan.

I did not get your point clearly.

One thing I would like to clear there is only one ISP and Same BGP AS no. 64356 is running on both HO-ISP & Sales-ISP.

Should I ask ISP to inject default route into bgp??

I already change the AD of bgp to prefer its route and am already redistributing bgp into ospf.

please guide me further if you quote some configuration example here I shall be grateful to you.

HO to HO-ISP(172.30.20.0 255.255.255.0)

Sales to Sales-ISP(172.30.19.0 255.255.255.0)

HO to Sales(192.168.1.0 255.255.255.0)

regards...

Hi,

I'd like to clarify first:

What do you exaclty mean by "I want my network to auto failover between the links."?

Are there any other router involved on your side?

Which prefixes are you receiving from your ISP? Full Internet BGP table on each site? Or just some partial routing info?

Are you redistributing the whole BGP table to OSPF on both your routers?

If yes, which part of failover is not working?

Best regards,

Milan

As you can see in topology, we have two paths from each branch HO & Sales to reach internet so I want my network switch over automatically in case of failure of one path.

In the current scenerio If I manually shutdown one side interface I am getting routes from otherside but the problem is that its not reverting back if primar link gets up.

we have some server applications here in HO & Sales which need to be accessed by remote branch.

Actually we have two remote sites connecting via ISP and we only receive that routes in BGP from ISP side.

Yes I am redistributing whole BGP table into OSPF.

Thanks & Regards,

Shahzad Ayub

Hi,

it's not clear to me why you need the whole Internet BGP table redistributed to OSPF.

I guess working with the default route only would be more effective.

But back to your problem:

Aren't you running mutual redistribution between BGP and OSPF?

I.e, aren't you also redistributing OSPF prefixes to your BGP?

That would explain why your failover connection would not revert back when the primary line gets Up again.

Best regards,

Milan

I am also redributing OSPF into BGP so that remote branches can get access to some applications in HO & Sales.

My topology is fully converged but the only problem is automatic failover.

I have the idea of IP SLA track but I down know which interface should I put track on???

Thanks & Regards,

Shahzad Ayub

Hi,

I believe I know what your problem could be.

It was discussed in this forum several times already, see https://supportforums.cisco.com/message/3372479#3372479 , e.g. (just replace EIGRP with OSPF in your case).

When you are running BGP/OSPF mutual redistribution, you need to be careful of the sequence in which the prefixes are received from particular routing protocols.

In your case, imagine following scenario on your HO router:

You've got a prefix received from BGP in your routing table. That prefix is redistributed to OSPF.

Then your Internet connection fails.

The prefix is withdrawn by your ISP and removed from your BGP table.

But you are still receiving the same prefix via OSPF (redistributed by your Sales router).

So it gets redistributed to BGP on your HO router (with BGP attribute weight=32768).

When your Internet connections gets Up again, your ISP starts advertising the prefix via BGP again.

But at the moment there is the same prefix in the BGP table of your HO router already with better weight.

So the prefix received from your ISP is worse from BGP process point of view now.

And the routing via OSPF remains active until you clear it manually.

To fix this, you need to modify the weight attribute as described in the thread mentioned above.

Best regards,

Milan