RE: [cobalt-users] DHCP with Windows and Macs

[Rodolfo Paiz <rpaiz@xxxxxxxxxxxxxx>]

I'm new to the list, and don't know if this has been covered in great detail
before. However, let me give you some general pointers. If they help, then
we can continue the conversation on-list or, if the list's most ancient
denizens have dealt with this many a time before, then you can mail me
privately and I'll see what I can do to help. Of course, I only have a
slightly better clue than you do, so doubtless greater minds will be
available for consultation.

In general, for security purposes, I'd suggest you only use routable
addresses for those things that *must* be accessible from the Outside. So,
let me use 1.1.1.1 through 1.1.1.6 to represent your real, routable IP's,
and 2.2.2.1 through 2.2.2.6 to represent your non-routable IP addresses.

Also, note that this is my best effort to help. The greater minds on this
list should carefully pick through this for errors, as I make no guarantee
that I'm right.

Qube Setup
==============================

Since the Qube has two Ethernet interfaces, let's give the Primary Ethernet
interface the 2.2.2.1 address and the Secondary port the 1.1.1.1 address.
Why? Your Primary goes to the internal network, hence a non-routable IP; the
converse applies to the Secondary, which goes to the Outside.

Now, create a DHCP scope. There's no need to make it a Class-C, but then
again there's no reason *not* to either, and it's always a pain redoing it
later. So, determine the MAC addresses (Ethernet adapter unique identifiers)
of the devices which should have static addresses and assign them reserved
2.2.2.x addresses based on their MAC address. I usually reserve a block,
like 2.2.2.2 through 2.2.2.40, which are either assigned statically or not
assigned at all.

I am assuming here that you have your own domain, and that your Qube is your
primary DNS for that domain. In your DNS settings, assign
"hp-laserjet-6p.yourdomain.com" to the static IP occupied by the printer.
You should have the Network Address Translation (NAT) box checked in your
Control Panel->Network->Ethernet settings. Hopefully, now when someone comes
in from the outside world and requests "hp-laserjet-6p.yourdomain.com", the
Qube will NAT the request and refer it to the internal IP, then route
packets appropriately.

Other static IP's between 2.2.2.2 and through 2.2.2.40 should be assigned to
computers or resources you want named and accessible. The routable IP's I'm
not sure what to do with, since I don't know if two different subnets can go
through a single gateway. Doesn't a gateway have to be on the same subnet as
the device? I dunno. But I think what I've outlined here will work. (BTW,
this is what I plan to do to get everything of mine working, but I'm pending
cable modem installation, thus don't actually have this up yet. I just know
it works internally...)

Then, make a scope for what's left of the 2.2.2.0 Class-C network (you'll
actually hand out addresses 2.2.2.41 through 2.2.2.254). These should be
assigned automatically. In DHCP client settings, you should ensure that all
clients use 2.2.2.1 as their gateway and also as their primary DNS.

You do not have to enable the Qube2 as a WINS server. As a matter of fact,
WINS is evil and a creation of people who do not respect RFC's. Hence, it
should never be used for anything; there is always a way (usually a better
way) to do things.

I hope this helps you; I'd also appreciate feedback from you on whether it
worked or not, and feedback from anyone else who care to comment on my
fledgling knowledge. Anyway, even if I'm dead wrong, just trying to help.

------
Rodolfo J. Paiz
rpaiz@xxxxxxxxxxxxxx <mailto:rpaiz@xxxxxxxxxxxxxx>