When enabled, RADIUS accounting sends command line accounting from the router to the RADIUS server. The router sends accounting records using UDP packets at port 1813 (decimal).
The router issues an accounting request packet for each event requiring the activity to be recorded by the RADIUS server. The RADIUS server acknowledges each accounting request by sending an accounting response after it has processed the accounting request. If no response is received in the time defined in the timeout parameter, the accounting request must be retransmitted until the configured retry count is exhausted. A trap is issued to alert the NMS (or trap receiver) that the server is unresponsive. The router issues the accounting request to the next configured RADIUS server (up to 5).
User passwords and authentication keys of any type are never transmitted as part of the accounting request.