5.5 NAS-Port

5.5. NAS-Port

Description

  This Attribute indicates the physical port number of the NAS which
  is authenticating the user.  It is only used in Access-Request
  packets.  Note that this is using "port" in its sense of a
  physical connection on the NAS, not in the sense of a TCP or UDP
  port number.  Either NAS-Port or NAS-Port-Type (61) or both SHOULD
  be present in an Access-Request packet, if the NAS differentiates
  among its ports.

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

0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Value +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Value (cont) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type

  5 for NAS-Port.

Length

  6

Value

  The Value field is four octets.