Round-Robin based on client IP

That would be the opposite of a persistence. You are right, chances are good to forward (redirect is a different story) to the same real server (pool member) in case of two members only. You are right, it will require a table based approach to make sure to select a different pool member for each new connection a client creates. In the iRule I would create a list of available pool members with each new CLIENT_ACCEPTED event. Next step would be to lookup the table having the client IP as key and the index of the selected pool member as value. As long as the value is less than the number of the available pool members the value is increased and now used as a pointer to pick a new target from the list created in the first step and update the value. If the value is greater than the number of available pool members in the list it will be initialized to point to the first in the list. Select pool member. Increase and update the value. Probably one hour to write and test. Cheers, Stephan