Subject: Very small networks

From: "Martin Djernaes" <[email-masked]>
Date: Thu, 20 Apr 2000 11:18:30 +0200

Hi,

Some days ago I asked "why shouldn't we NAT a link local address", and
have been very happy with the nice feedback from the group. The
background for my question were that I see zeroconf networks mostly as
home networks or very small office networks without an administrator
with a detailed knowledge about how to configure such network, but of
cource with all the requirements which you can imagine.

When this is said I also expect 99% of all these networks to be
connected to the Internet, with some kind of gateway. Since I just have
said that we are dealing with small users, the chance that the user will
take some kind of low price Internet connection is pretty high, again
making the reason for deploying NAT at the interface to the Internet
pretty big.

I can't help wondering how to deploy a (flexible) zero configuration
network with a mixture of new and old devices. Windows PCs do not have
anything like a DHCP server, Win98 actually include the IPv4 autoconfig
option. A lot of other devicves must be configured manually with IP
address etc, and some are permanent a DHCP client. So what is going to
happen if I have two Win98 machines in a network (configured with IPv4
AutoConfig), and I now add a NAT able router with a DHCP server for
assigning addresses. The two Win98 machines get another IP address
(eventually in another address range), but what happens to my old low
price printer "adapter" which I manually have configured with a
169.254.0.x address (how should Windows/WhatEverOS recognize that the
same printer is now avalible on another address)? Or my Win95 machine
which also use a manually configured address, since Win95 do only
support manual assignment and DHCP assignment?

How do the zeroconf working group address the problem of "backward
compatibility"?

For me it also looks like that the zero working group have said that if
some kind of "non zero configuration service is available, we will back
100% out of this business, and let the user decide". I can't help
thinking that a user who want to configure everything heimself/herself
will be able to explicit turning it off (could be via a zeroconf
service). The user who do not want to configure things, will get pretty
big problems when he suddenly apply new devices which have some services
which is not transparent for him. How do we provide this?

Regards,
  Martin Djernæs