DHCP Option to Disable Stateless Auto-Configuration in IPv4 Clients (RFC2563)
Original Publication Date: 1999-May-01
Included in the Prior Art Database: 2019-Feb-11
Internet Society Requests For Comment (RFCs)
This document describes a mechanism by which DHCP servers are able to tell clients that they do not have an IP address to offer, and that the client should not generate an IP address it's own. [STANDARDS-TRACK]
Network Working Group R. Troll Request for Comments: 2563 @Home Network Category: Standards Track May 1999
DHCP Option to Disable Stateless Auto-Configuration in IPv4 Clients
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 (1999). All Rights Reserved.
Operating Systems are now attempting to support ad-hoc networks of two or more systems, while keeping user configuration at a minimum. To accommodate this, in the absence of a central configuration mechanism (DHCP), some OS’s are automatically choosing a link-local IP address which will allow them to communicate only with other hosts on the same link. This address will not allow the OS to communicate with anything beyond a router. However, some sites depend on the fact that a host with no DHCP response will have no IP address. This document describes a mechanism by which DHCP servers are able to tell clients that they do not have an IP address to offer, and that the client should not generate an IP address it’s own.
With computers becoming a larger part of everyday life, operating systems must be able to support a larger range of operating environments. One aspect of this support is the selection of an IP address. The Dynamic Host Configuration Protocol [DHCP] provides a superb method by which site administrators may supply IP addresses (and other network parameters) to network devices. However, some operating environments are not centrally maintained, and operating systems must now be able to handle this quickly and easily.
IPv6 accounts for this, and allows an IPv6 stack to assign itself a global address in the absence of any other mechanism for configuration [IPv6SAC]. However, Operating System designers can’t wait for IPv6 support everywhere. They need to be able to assume
Troll Standards Track [Page 1]
RFC 2563 DHCP Auto-Configuration Option May 1999
they will have IPv4 addresses, so that they may communicate with one another even in the smallest networks.
This document looks at three types of network nodes, and how IPv4 address auto-configuration may be disabled on a per-subnet (or even per-node) basis. The three types of network nodes are:
* A node for which the site administrator will hand out configuration information,
* A node on a network segment for which there is no site administrator, and
* A node on a network segment that has a central site administrator, and that administrator chooses not to hand out any configuration information to the node.
The difference between the second and third cases is the clients behavior.
In one case, the node may assign itself an IP address, and have full connectivity with...