NimbostratusHey Carl
I'm guessing you have configured a Sync/Failover Device Group with both i2800 LTM appliances as members?
In order to have them failed over based on TMM interfaces (client interfaces) you will have to configure specific details to handle this.
What you can do is either configure VLAN Failsafe - K13297: Overview of VLAN failsafe (10.x - 13.x)
When you configure VLAN failsafe, the BIG-IP system monitors network traffic on the VLAN. If the BIG-IP system detects a loss of network traffic on the VLAN, the VLAN failsafe timer begins and the BIG-IP system attempts to generate traffic to nodes or the default router that is accessible through the VLAN.
Or use HA Groups - K42542000: Video: Using the HA group feature
Which one of these you should use depends on your setup. With VLAN Failsafe, you need to assign a VLAN that you know for sure will always exist and have traffic on. If this VLAN is removed on any adjacent devices or modified on the BIG-IP, it will cause a failover.
With HA Groups I usually just assign the Trunk Interfaces and assign an Active Bonus. If one of the interfaces in the Trunk fails, it will not failover. But, if all interfaces in the trunk goes down, it will trigger a failover. But HA Groups is more complex as you need to calculate a weight of each configuration object and when it should failover. Also, you will not be able to use Force To Stanby feature or the auto-failback feature since you are letting the BIG-IP caluclate the best BIG-IP to be active.
I hope this gets you started. Please let me know if you have any further questions.
