HELP! hanging iRule

I haven't tested any of this, but I would mention a couple things. You are using tcp::client_port where I think that is going to be the source port. You would want to use tcp::local_port which is the destination port.

Also, you're doing when HTTP_Request when you should probably be using when CLIENT_ACCEPTED. This happens higher in the stack, so it should be more efficient.

Something like this:

 
 when CLIENT_ACCEPTED { 
 if { [TCP::local_port] equals 531 } { 
 pool win2003 
 } elseif { [TCP::local_port] equals 25 } { 
 pool win2003 
 } else { 
 pool win2003 
 }}