RADIUS Attribute - NAS Identifier

As per RFC 2865

This Attribute contains a string identifying the NAS originating the Access-Request. It is only used in Access-Request packets. Either NAS-IP-Address or NAS-Identifier MUST be present in an Access-Request packet. Note that NAS-Identifier MUST NOT be used to select the shared secret used to authenticate the request. The source IP address of the Access-Request packet MUST be used to select the shared secret.

A summary of the NAS-Identifier Attribute format is shown below.  The fields are transmitted from left to right.

Open

Type = 32 for NAS-Identifier.

Length = (>= 3)

String = The String field is one or more octets, and should be unique to the NAS within the scope of the RADIUS server. For example, a fully qualified domain name would be suitable as a NAS-Identifier. The actual format of the information is site or application specific, and a robust implementation SHOULD support the field as undistinguished octets. The codification of the range of allowed usage of this field is outside the scope of this specification.