With the following CLI commands, you can define or view the source port range that the gateway uses to register to Communication Manager:
set registration source-port-range
show registration source-port-range
set registration default source-port-range
If you do not specify a range, the gateway will select a port within the default range of 1024 to 65535.
In Edge mode, if the registration source port range is configured to use a small range of ports, the gateway might fail to register with Communication Manager after a gateway reboot. For example, use the command set registration source-port-range 1024 1025 for specifying the port range.
Use as wide a range as possible when using the set registration source-port-range command or use the set registration default source-port-range command to define the source port range.