1. Introduction

Cette section conserve le texte RFC pour DHCPv4 over DHCPv6 with Relay Agent support, y compris le comportement relay, les topology-discovery diagrams, les notes de deploiement, les considerations de securite et le statut IANA.

1.  Introduction

   [RFC7341] describes a transport mechanism for carrying DHCPv4
   [RFC2131] messages using DHCPv6 [RFC9915] for dynamic provisioning of
   IPv4 addresses and other DHCPv4-specific configuration parameters
   across IPv6-only networks.  The deployment of [RFC7341] requires
   support in DHCP clients and at the DHCPv6 server.  However, if a
   client is embedded in a host that only supports IPv4 and cannot
   easily be replaced or updated (which could be due to any number of
   technical or business reasons), this approach does not work.

   Similarly, the DHCPv6 Relay Agent specification defined in [RFC9915],
   which also refers to [RFC6221] for the Lightweight DHCPv6 Relay Agent
   (LDRA) behavior, does not provide any mechanism to handle legacy
   DHCPv4, except by requiring the client to implement the DHCPv4-over-
   DHCPv6 encapsulation and decapsulation.

   This document specifies a solution based on [RFC7341] that can be
   implemented in intermediate nodes such as switches or routers,
   without putting any requirements on clients.  No new protocols or
   extensions are needed; instead, this document specifies a new use
   case for [RFC7341] that allows a Relay Agent to perform the DHCPv4-
   over-DHCPv6 encapsulation and decapsulation instead of the client.

1.1.  Applicability Scope

   The mechanisms described in this document apply to the configuration
   phase of hosts that need to receive an IPv4 address when a DHCP
   server for IPv4 [RFC2131] is not reachable directly from the host.
   Furthermore, the host is unable to implement a DHCP client conformant
   to [RFC7341], as it is connected to an IPv4-only network.  However,
   there is a DHCPv6 server that can provide IPv4 addresses by means of
   the mechanisms specified in [RFC7341].