Specifies the default UDP port on the destination Hosts to which Radiator will send authentication requests. The argument may be either a numeric port number or an alphanumeric service name as specified in /etc/services (or its moral equivalent on your system). The default port is 1645. Note that the officially assigned port number for RADIUS accounting has been changed to 1812. AuthPort may contain special formatting characters. Can be overridden for an individual host inside its Host clause.

# Send authentication to port 1812 on the remote server
AuthPort 1812