RADIUS

Name

Accounting-Request

Synopsis

Packet Type	Request
Code	4
Identifier	Unique for each request; unique for each transmission of modified data
Authenticator	Request
Attribute Data	0 or more attributes

Accounting-Request packets are sent from the client to the server. Remember that a client can be a true RADIUS client or another RADIUS server acting as a proxy. The client sends the packet with the code field set to 4. When the server receives this request packet, it is required to transmit an acknowledgment to the client unless it cannot handle or process the packet. In this case, it cannot transmit anything to the client.

With the exceptions of the User-Password, CHAP-Password, Reply-Message, and State attributes, any other attribute allowed in an Access-Request or Access-Accept packet can be used inside an Accounting-Request packet.

Tip

Chapter 3 discusses all standard RADIUS attributes and their properties, including the packets in which they are allowed to be included. Check there for a complete overview of packet presence requirements.

There are a couple more caveats to presence in the packet. As mentioned in Chapter 2, the NAS-IP-Address and NAS-Identifier attributes are mutually exclusive, meaning that one or the other must be included in a packet, but not both. The RFC recommends distinguishing the NAS port or type of port in the packet by using the NAS-Port or NAS-Port-Type attributes unless that information is superfluous to the service. Additionally, the ...