forward traffic to multi pools and add x port to original port

up

The easiest way to add a digit to a port is simply concatenating the number:

when CLIENT_ACCEPTED {
    node 10.70.0.2:1[TCP::local_port]
}

For example, that will send a client request on port 1000 to port 11000.

You'd use the pool command to forward traffic to a load balanced pool, and the node command to send traffic to a specific IP and port. Your original description sounded like you just needed to add a 1 to the incoming port. If you simply forward traffic to different pools, port translation in the virtual server will change the port to the port of the selected pool member.

Do you just need to send traffic to specific pools, or do you need to send traffic to specific members within pools?

Okay, so I'm not accounting for how you make a pool selection here, but the following is a very simple way to choose a pool member and then forward traffic to that member on a derived port. This assumes of course that the pool members are all listening on multiple ports and that the VIP is listening on multiple (all) ports.

when HTTP_REQUEST {

     select the pool (your pool selection will differ)     
    pool pool1

     force an early load balancing decision and store the chosen server IP in a variable
    set srv [lindex [LB::select] 3]

     direct the request to the chosen pool member on the derived port (1[TCP::local_port])
    node $srv:1[TCP::local_port]
}