CSS 11503 Box to Box Redundancy Not Working Properly

Unanswered Question
Oct 15th, 2009


I have a problem with my pair of CSS 11503 running box-to-box redundancy with ip redundancy master turned on.

Everytime CSS1 is shut down and powered up, it will resume the master role. However, when this happens, all connections to the VIPs wont work (for example, telnet port 80). The connections however do work when connecting to the actual servers (physical ip address). Please advise.


I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
jason.espino Thu, 10/15/2009 - 22:08

This issue is pretty odd, it seems as though in the event of a failure and the secondary unit becomes active it doesn't perform a gratuitous ARP to inherit the MAC address of the primary unit. Would it be possible to provide a copy of the configuration on the CSS?

- Jason

glenn.lim Thu, 10/15/2009 - 22:29


The scenario is like this. CSS1 and CSS2 are in a box-to-box redundancy with ip redundancy master configured on CSS1.

Everytime CSS1 goes down, CSS2 will assume the active role and everything works fine. The problem only occurs when CSS1 comes back alive, assuming the master role. Then, all the connections will not be working properly. Attached is the config of both CSS. Thanks.

jason.espino Thu, 10/15/2009 - 23:38


The configurations look good however, I am curious as to why the "app" command is not enabled on the CSS02? When a failure occurs from CSS1 to CSS2, and the moment CSS1 comes back alive and preempts to become master what information do you see exchanged between the 2 CSS's within the sys.log during this event?

- Jason

glenn.lim Thu, 10/15/2009 - 23:42


I'm pretty new to CSS. Where can i view this sys.log file


jason.espino Fri, 10/16/2009 - 00:27


I would definitely enable "app" on CSS02 1st. When a failure occurs or when the devices are just communication(syncing configs) you should be able to see various APP and VRRP messages sent/stored in the sys.log file on the CSS.

Running the following command should show some useful information.

"sho log sys.log tail 200"

The "tail" command is optional. The above command will allow you to view the last 200 messages stored in the sys.log file on the CSS.

- Jason

glenn.lim Fri, 10/16/2009 - 02:06


I have enable "app" on CSS02 already but still faces the same problem. WIll take a look at the logs to see more.

Based on the config i sent, anything else you feel is not configured properly?


sean.cheney Fri, 10/16/2009 - 07:00

You can not expect completely transparent failover/failback without any interruption.

Does it still break when you restart teh client(telnet session for example?

You need to configure adaptive session redundany for that to be reliable.

glenn.lim Fri, 10/16/2009 - 18:00


Client session wont work even it is restarted. Have left the CSS untouched for more than an hour after CSS01 has booted up and still, it wont work


This Discussion