RADIUS attribute from rfc3162
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-IPv6-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 99 for Framed-IPv6-Route Length >=3 Text The Text field is one or more octets, and its contents are implementation dependent. The field is not NUL (hex 00) terminated. It is intended to be human readable and MUST NOT affect operation of the protocol. For IPv6 routes, it SHOULD contain a destination prefix 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, a space, and one or more metrics (encoded in decimal) separated by spaces. Prefixes and addresses are formatted as described in . For example, "2000:0:0:106::/64 2000::106:a00:20ff:fe99:a998 1".Whenever the gateway address is the IPv6 unspecified address the IP address of the user SHOULD be used as the gateway address. The unspecified address can be expressed in any of the acceptable formats described in . For example, "2000:0:0:106::/64 :: 1".