Subject: WG Review: Zero Configuration Networking (zeroconf)

From: Steve Coya <[email-masked]>
Date: Thu, 02 Sep 1999 09:31:02 -0400

A new IETF working group has been proposed in the Internet Area.
The IESG has not made any determination as yet. 

The following Description was submitted, and is provided for
informational purposes only:

Zero Configuration Networking (zeroconf)
=======================================

 Current Status: Proposed Working Group

The goal of the Zero Configuration Networking (ZEROCONF) Working Group
is to enable networking in the absence of configuration and 
administration.  Zero configuration networking is required for 
environments where administration is impractical or impossible, 
such as in the home or small office, embedded systems 'plugged 
together' as in an automobile, or to allow impromptu networks as 
between the devices of strangers on a train.
 
ZEROCONF requirements will make networking as easy as possible, but
no easier.  In some cases other considerations may dominate ease of 
use.  For example, network security requires some configuration which 
may not be as easy as the unacceptable alternative of 'no security.'

Networks where ZEROCONF protocols apply can include (but are not limited 
to) environments where no DHCP, MADCAP or DNS servers are present.  

This working group will address both IPv4 and IPv6. 

Many functions which are not of fundamental importance to host and 
application configuration are outside the scope of the working group.
This is not because there are no other problems to solve for networking
in an environment without administration.  This working group will
focus on an achievable subset of these problems.  The ZEROCONF WG will 
precisely define the requirements for each of the following functions:

  * Automatic Host Configuration (IP address, network prefix, gateway
    router location, DNS server location) 

  * Name-to-Address Translation 

  * Service Discovery 

  * Automatic allocation of Multicast Addresses 

  * Sufficient security features to prevent ZEROCONF networks from being
    abused

The working group will define the requirements to provide these 
functions on two distinct network topologies:

  1. A single network segment, where all hosts are reachable by 
     link-layer broadcast or multicast messages.  

  2. A set of network segments, (on different IP subnetworks) 
     interconnected by a single router.

Automatic configuration of an arbitrary topology of routers and subnets
is out of the scope of the ZEROCONF WG charter.

The working group will also define how such a network will automatically 
transition from 'administered' to 'unadministered' behavior, as well as 
from 'unadministered' to 'administered'.  That is, the same hosts must
be able to function on networks with no configuration as well as be 
capable of direct IP connectivity to the global Internet, including 
DNS entries supplied through standard DNS services.  It is also possible 
that both modes (ZEROCONF and administered) may coexist on the same 
network; the modes may not be exclusive of each other.

When ZEROCONF networks or hosts which are configured using ZEROCONF 
protocols are connected to the big 'I' internet, they should not 
automatically become vulnerable to new security threats.

This WG will produce two documents.  The first describes the 
requirements for the configuration (and security) services, defaults, 
and mechanisms a node needs to fully participate on ZEROCONF networks 
and/or configured networks.  The second, which follows the first, will 
detail a 'profile' specifying which standards specifically satisfy 
ZEROCONF requirements.

The WG will not engage in any new protocol work.  If there is no 
existing standard protocol which satisfies ZEROCONF requirements, the 
profile document may specify that a new protocol should be developed or 
recommend a change to an existing standard to apply to the ZEROCONF 
environment.