RFC 3527 (rfc3527) - Page 1 of 9
Link Selection sub-option for the Relay Agent Information Option for DHCPv4
Alternative Format: Original Text Document
Network Working Group K. Kinnear
Request for Comments: 3527 M. Stapp
Category: Standards Track R. Johnson
J. Kumarasamy
Cisco Systems
April 2003
Link Selection sub-option
for the Relay Agent Information Option for DHCPv4
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
This document describes the link selection sub-option of the relay-
agent-information option for the Dynamic Host Configuration Protocol
(DHCPv4). The giaddr specifies an IP address which determines both a
subnet, and thereby a link on which a Dynamic Host Configuration
Protocol (DHCP) client resides as well as an IP address that can be
used to communicate with the relay agent. The subnet-selection
option allows the functions of the giaddr to be split so that when
one entity is performing as a DHCP proxy, it can specify the
subnet/link from which to allocate an IP address, which is different
from the IP address with which it desires to communicate with the
DHCP server. Analogous situations exist where the relay agent needs
to specify the subnet/link on which a DHCP client resides, which is
different from an IP address that can be used to communicate with the
relay agent.
1. Introduction
In RFC 2131, the giaddr specifies an IP address which determines a
subnet (and from there a link) on which a DHCP client resides as well
as an IP address which can be used to communicate with the relay
agent. The subnet-selection option [RFC 3011] allows these functions
of the giaddr to be split, so that when one entity is performing as a
Kinnear, et al. Standards Track