session add command behavior

You can test this by running the iRule a few times where the same client IP will have multiple nexthop values and then logging the value of the session lookup command. I expect the existing key will be updated with the new value. Here is a simple iRule which demonstrates this:

 
 when HTTP_REQUEST { 
  
    session add uie key1 value1 
    session add uie key1 value2 
 log local0. "\[session lookup uie key1\]: [session lookup uie key1]" 
 } 
 

Log output:

: [session lookup uie key1]: value2

Also, to allow for variable expansion (of $session_key) or of commands (like IP::client_addr), you should replace the curly braces in the session command with:

session add uie [list [IP::client_addr] any virtual] [LINK::nexthop] 800

Aaron