Selecting UDP ports

When you select a UDP port, select an available 16-bit integer from the range that follows:

To check which ports are defined as defaults for a node, examine the file /etc/services. You should also use the netstat command to list the UDP ports currently in use. For example:

# netstat -a | more
UDP
   Local Address         Remote Address     State
-------------------- -------------------- -------
      *.sunrpc                              Idle
      *.*                                   Unbound
      *.32771                               Idle
      *.32776                               Idle
      *.32777                               Idle
      *.name                                Idle
      *.biff                                Idle
      *.talk                                Idle
      *.32779                               Idle
.
.
.
      *.55098                               Idle
      *.syslog                              Idle
      *.58702                               Idle
      *.*                                   Unbound

Look in the UDP section of the output; the UDP ports that are listed under Local Address are already in use. If a port is listed in the /etc/services file, its associated name is displayed rather than the port number in the output.