RADIUS attribute from rfc2868
This Attribute contains the address of the initiator end of the
tunnel. It MAY be included in both Access-Request and Access-
Accept packets to indicate the address from which a new tunnel is
to be initiated. If the Tunnel-Client-Endpoint Attribute is
included in an Access-Request packet, the RADIUS server should
take the value as a hint; the server is not obligated to honor the
hint, however. This Attribute SHOULD be included in Accounting-
Request packets which contain Acct-Status-Type attributes with
values of either Start or Stop, in which case it indicates the
address from which the tunnel was initiated. This Attribute,
along with the Tunnel-Server-Endpoint and Acct-Tunnel-Connection-
ID attributes, may be used to provide a globally unique means to
identify a tunnel for accounting and auditing purposes.
A summary of the Tunnel-Client-Endpoint 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 | Tag | String ...
66 for Tunnel-Client-Endpoint.
The Tag field is one octet in length and is intended to provide a
means of grouping attributes in the same packet which refer to the
same tunnel. If the value of the Tag field is greater than 0x00
and less than or equal to 0x1F, it SHOULD be interpreted as
indicating which tunnel (of several alternatives) this attribute
pertains. If the Tag field is greater than 0x1F, it SHOULD be
interpreted as the first byte of the following String field.
The format of the address represented by the String field depends
upon the value of the Tunnel-Medium-Type attribute.
If Tunnel-Medium-Type is IPv4 (1), then this string is either the
fully qualified domain name (FQDN) of the tunnel client machine,
or it is a "dotted-decimal" IP address. Conformant
implementations MUST support the dotted-decimal format and SHOULD
support the FQDN format for IP addresses.
If Tunnel-Medium-Type is IPv6 (2), then this string is either the
FQDN of the tunnel client machine, or it is a text representation
of the address in either the preferred or alternate form .
Conformant implementations MUST support the preferred form and
SHOULD support both the alternate text form and the FQDN format
for IPv6 addresses.
If Tunnel-Medium-Type is neither IPv4 nor IPv6, this string is a
tag referring to configuration data local to the RADIUS client
that describes the interface and medium-specific address to use.