DHCP reconfigure extension (RFC3203)
Original Publication Date: 2001-Dec-01
Included in the Prior Art Database: 2019-Feb-13
Internet Society Requests For Comment (RFCs)
Y. T'Joens: AUTHOR [+2]
This document defines extensions to DHCP (Dynamic Host Configuration Protocol) to allow dynamic reconfiguration of a single host triggered by the DHCP server (e.g., a new IP address and/or local configuration parameters). [STANDARDS-TRACK]
Network Working Group Y. T’Joens Request for Comments: 3203 C. Hublet Category: Standards Track Alcatel P. De Schrijver Mind December 2001
DHCP reconfigure extension
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 (C) The Internet Society (2001). All Rights Reserved.
This document defines extensions to DHCP (Dynamic Host Configuration Protocol) to allow dynamic reconfiguration of a single host triggered by the DHCP server (e.g., a new IP address and/or local configuration parameters). This is achieved by introducing a unicast FORCERENEW message which forces the client to the RENEW state. The behaviour for hosts using the DHCP INFORM message to obtain configuration information is also described.
The procedures as described within this document allow the dynamic reconfiguration of individual hosts.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY" and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].
2. DHCP force renew
This section describes the FORCERENEW message extension.
T’Joens, et al. Standards Track [Page 1]
RFC 3203 DHCP reconfigure extension December 2001
DHCP client : host to be reconfigured using DHCP.
DHCP server : server which configured the DHCP client.
2.2 Force renew procedures
The DHCP server sends a unicast FORCERENEW message to the client. Upon receipt of the unicast FORCERENEW message, the client will change its state to the RENEW state, and will then try to renew its lease according to normal DHCP procedures. If the server wants to assign a new IP address to the client, it will reply to the DHCP REQUEST with a DHCP NAK. The client will then go back to the init state and broadcast a DHCP DISCOVER message. The server can now assign a new IP address to the client by replying with a DHCP OFFER. If the FORCERENEW message is lost, the DHCP server will not receive a DHCP REQUEST from the client and it should retransmit the FORCERENEW message using an exponential backoff algorithm. Depending on the bandwidth of the network between server and client, the server should choose a delay. This delay grows exponentially as retransmissions fail. The amount of retransmissions should be limited.
The procedures described above assume the server to send a unicast FORCERENEW message to the client. Receipt of a multicast FORCERENEW message by the client should be silently discarded.
It can be that a client has obtained a network address through some other means (e.g., manual configuration) and has used a DHCP INFORM request to obtain other local configuration par...