RPC load balancing among multiple tiers using iRules, pools and forwarding

I'm not sure if you are asking a question here?

I will make a couple of notes though.

First, TCP::server_port will likely return 0 in the CLIENT_ACCEPTED event. This is because the backend connection has yet to be made and we made the following changes from 4.x:

client = clientside remote

server = serverside remote

remote = clientside source or serverside destination

local = clientside destination or serverside source

So, TCP::server_port refers to the serverside TCP::remote_port or the serverside's destination port. At the time CLIENT_ACCEPTED is evaluated, the proxy hasn't connected the serverside, so this information is not yet available. You probably want to use TCP::local_port instead.

Second, your last two rules look identical and you could probably simply use the same rule for both virtuals.

Third, you could probably use a condensed if expression or a switch statement in the second rule since all the cases use a forward.

As a single if:

when CLIENT_ACCEPTED {
   if { [TCP::local_port] == 135 or \
        [TCP::local_port] == 3372 or \
        [TCP::local_port] == 7495 or \
      ( [TCP::local_port] >= 40000 and [TCP::local_port] < 45000 ) } {
      forward
   } else {
      discard
   }
}

As a switch:

when CLIENT_ACCEPTED {
   switch -glob [TCP::local_port] {
      135 -
      3372 -
      7495 -
      4[01234]??? { forward }
      default { discard }
   }
}