Can I bind a virtual server port to real server port via iRule for every connection

Is the destination port of the incoming traffic to the LTM different from the port the server listening to?

Is the destination port of the incoming traffic to the LTM different from the port the server listening to?

Can you tell us what you are trying to do overall. I get the impression this is only part of the picture.

How does the payload looks like with the port information?

How does the payload looks like with the port information?

I assume 2 bytes referred is in TCP payload.

Try this:

when CLIENT_ACCEPTED {
    TCP::collect
}
when CLIENT_DATA {
   set port [TCP::payload 2]
   TCP::release
}
when LB_SELECTED {
  node [LB::server addr] $port
  LB::reselect
}