iRule to not allow traffic to pool member in 'unknown' state

If the Server State is what you are after as a qualifier of the health and status of the server then the default and custom monitors that can be assigned to the Pool and Pool Member level are your best option.

 

 

Even the active_members check that can be done to verify that there are pool members available relies on the monitors that are assigned to the server or server pool.

 

 

As hoolio pointed out, using an iRule over the built in functionality of the LTM is a waste of resources.

 

 

Hope this helps.