RADIUS Accounting Server Port

RADIUS accounting normally uses UDP port:

1813	IANA-specified port. The SonicWall network security appliance listens on port 1813 by default.
1646	An older, unofficial, standard port.

Other port numbers can be configured for the RADIUS accounting port, but the SonicWall Security Appliance can listen on only one port. So, if you are using multiple network access servers (NASs), they must all be configured to communicate on the same port number.