Hi Daniel,
The FT Query VLAN interface is an optional, yet very good, feature to be used when using redundant ACE modules or appliances. Without it, if the FT VLAN was to go down, the standby ACE will no longer receive FT heartbeats from the active ACE and therefore take the active role. However, if the active ACE is still running fine in the active role, then you don't want the standby ACE to take over as active because that will put them into an active/active scenario, which may lead to connectivity issues.
This is where the FT Query VLAN interface comes in. If the FT VLAN goes down, the standby ACE will notice this, but before taking the active role, it will ping it's peer IP address configured on the interface that is designated as the FT Query VLAN. If the ping is successful, then it will stay in the standby role, thereby saving you some headaches.
The status that you are seeing is the ACE's way of telling you that the interface is UP, but if you want to know if it can successfully ping the peer IP address, then you would have to manually ping the peer IP address from the CLI. The ACE does not periodically check the ping connectivity through any automatic mechanism. The automatic mechanism is only triggered by the FT VLAN going down.
Does this help?
Sean
