JMX, RMI and firewalls

Hi - we are using JMX to talk between a couple of Resin servers to 
invoke mbeans.  The problem is that whilst resin accepts 
-Dcom.sun.management.jmxremote.port=8181 when RMI is called it used a 
random high number port to communicate (in the example below it is 
57726.  Is it possible in Resin to define a specific port for RMI in 
this instance?

11:20:14.859044 IP res01.57681 > res02.57726: S 2600566516:2600566516(0) 
win 5840 <mss 1460,sackOK,timestamp 2352882713 0,nop,wscale 2>

Thanks

Dave