RADIUS attribute from rfc2865


Framed-Route

This Attribute provides routing information to be configured for
      the user on the NAS.  It is used in the Access-Accept packet and
      can appear multiple times.

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

    0                   1                   2
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
   |     Type      |    Length     |  Text ...
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-Type

      22 for Framed-Route.

   Length

      >= 3

   Text

      The Text field is one or more octets, and its contents are
      implementation dependent.  It is intended to be human readable and
      MUST NOT affect operation of the protocol.  It is recommended that
      the message contain UTF-8 encoded 10646  characters.

      For IP routes, it SHOULD contain a destination prefix in dotted
      quad form optionally followed by a slash and a decimal length
      specifier stating how many high order bits of the prefix to use.
      That is followed by a space, a gateway address in dotted quad
      form, a space, and one or more metrics separated by spaces.  For
      example, "192.168.1.0/24 192.168.1.1 1 2 -1 3 400". The length
      specifier may be omitted, in which case it defaults to 8 bits for
      class A prefixes, 16 bits for class B prefixes, and 24 bits for
      class C prefixes.  For example, "192.168.1.0 192.168.1.1 1".

      Whenever the gateway address is specified as "0.0.0.0" the IP
      address of the user SHOULD be used as the gateway address.