To: iana@isi.edu
Subject: Request for DHCP Options for Circuit-Mode Relay Agents
Date: Wed, 09 Oct 1996 11:51:20 -0400
From: "Michael W. Patrick" <mpatrick@dma.isg.mot.com>


X.X Agent Circuit ID

This option MAY be added by DHCP relay agents which terminate switched
or permanent circuits.  It encodes a agent-local identifier of the
circuit from which a DHCP discover/request packet was received.  It is
intended for use by agents in relaying DHCP responses back to the
proper circuit.  Possible uses of this field include

    - Router interface number
    - Switching Hub port number
    - Remote Access Server port number
    - Frame Relay DLCI
    - ATM virtual circuit number
    - Cable Data virtual circuit number

The format of the Agent Circuit ID may be further standardized by IETF
working groups responsible for IP communication on that type of
circuit.  In the absence of such standardization, the format may
proprietary to the relay agent vendor.

DHCP servers supporting this option MUST return the option value
unchanged in all Offer and Ack responses.  Servers MAY use the
information for IP and other parameter assignment policies, but care
should be taken due to the potential proprietary format.  The DHCP
server MAY report the Agent Circuit ID value of current leases in
statistical reports (including its MIB) and in logs.

 Code   Len     Circuit ID
+------+------+------+------+------+------+------+------+--
|  82  |   n  |  c1  |  c2  |  c3  |  c4  |  c5  |  c6  | ...
+------+------+------+------+------+------+------+------+--