Changing destination pool TCP port via iRules

This takes a class that has special TCP payload data that is mapped to a specific destination port. TCP is collected and analyzed for that special data, if it exists, findclass will pull out the appropriate port number and set the variable new_port, which you can then use in the LB_SELECTED event to direct to the appropriate pool member. Is this what you're looking for?

class port_map {
 "special_data1 port1"
 "special_data2 port2"
 "special_data3 port3"
 ...
 "special_data1500 port 1500"
}
when CLIENT_ACCEPTED {
  TCP::collect XX
}
when CLIENT_DATA {
  if { [TCP::payload XX] contains "myData" } {
     set new_port [findclass [TCP::payload XX] $::port_map " " ]
  } 
 TCP::release
}
when LB_SELECTED {
  pool [LB::server pool] member [LB::server addr] $new_port
}