Hello Ahmed
You say that the current configuration you posted is working, correct? I suggest you follow these troubleshooting steps:
- Attempt to simply change the AD of the second default route from 10 to 1 (return it to the default). This will make both routes equal and should result in equal cost load balancing.
- Next, verify that load balancing is indeed taking place. You can add some ACLs on the outbound interfaces with permit statements and have them log traffic. Check to see that traffic is indeed being sent from both interfaces. You may also want to check your NAT translations to see that translations are taking place on both interfaces as well.
- Once that is done, then you can simulate a failure. Don’t shut down the interface on this router, but shut down the interface on the next-hop router that corresponds to the 192.168.80.169 IP. Check connectivity, and check the access list logs for each interface.
I suspect that the issue has to do with the application of the same NAT translations on multiple load-balanced interfaces, but without doing the testing I cannot be sure. As you follow this procedure, you should see when and under what circumstances the failure takes place, and this should give you a good indication of where the problem is.
Let us know your results and get back to us for further troubleshooting steps if needed.
I hope this has been helpful!
Laz