The radius client obtains the radius socket ports to use via the '/etc/services' file. The client only looks up the lines starting with 'radius' and 'radacct'.

• Modify the /etc/services file as follows. Change lines starting with 'radius' and 'radacct' to the socket numbers you wish. For example:
  radius 1645/tcp
  radius 1645/ucp
  radacct 1646/tcp
  radacct 1646/ucp

• After editing /etc/services copy it to /usr2
  cp /etc/services /usr2

• Edit /usr2/rc.user and add the following line just above "exit 0":
  cp -a /usr2/services /etc/services

• reboot
  

If you factory default the unit, the '/usr2/rc.user' script file is moved to '/usr2/rc.user.old#' and the default rc.user file will be restored.