Re: DHCPCD on an internal LAN

On Mon, 10 Dec 2007 23:55:24 +0000, Mike wrote:

Responding to Ivan Marsh...
On Mon, 10 Dec 2007 22:04:40 +0000, Mike wrote:

Responding to Ivan Marsh...
On Mon, 10 Dec 2007 20:55:21 +0000, Mike wrote:

I just confused myself trying to set up dnsmasq on P2 so that other
machines on my internal lan connect in the same way (to P2) using
their dhcpcd rather than static IPs.

I'm getting the idea dnsmasq was designed to provide a method of
routing an internal machine through a gateway machine and out to the
external DHCP server (in this case this would be my broadband service
provider).

If I get what you're trying to do here you're not going to have much
luck. Your provider will only allow one IP address to be DHCPed to you
local network, the rest have to come from your internal network.

If you want dynamic internal addresses you have to run a DHCP server on
your Internet connected machine and run IP masquerading to route the
traffic.

Quite the opposite. I don't want the LAN machines to ever connect to the
internet at all. The only machine that should ever connect to the
internet should be the P2 machine. All others on the LAN should only be
able to SSH into an account on the P2 and run P2 applications remotely
via SSH to surf etc. Therefore, only one machine ever goes online (the
P2), and only one internet connection required. And, each internal LAN
machine should remain isolated from any other on the LAN. A kind of
"blind tentacle" arrangement with the P2 as head.

Okay.

No laughter so far. Thats a good sign. ;)

My problem is getting the local machines to ask the P2 for internal LAN
IP addresses, using DHCPCD as they boot up on the LAN, rather than
configuring everything with static IPs as I currently have things.

That's just a matter of installing a DHCP server on the P2 machine that
services the internal LAN then.

Thats just what I thought! :)

So, is dnsmasq the tool for the job. or am I looking at a high speed
run down the other side of the learning curve when I realise I
misread something about what dnsmasq was designed to do?

No. dnsmasq would appear to do exactly the opposite of what you're trying
to do.

As for isolating the internal machines, if the P2 machine isn't offering
them any route to the internet then they won't have one... or one better,
changing the firewall to explicitly prevent a route to the internet.

Already done. As I mentioned, its already been set up with static
IPs. I just need to replace that function with a dynamic setup rather
than a static one, so I don't have to manually configure various
things that might get plugged into the internal LAN. Their DHCP
should be able to ask for and get an IP address from P2
automatically.

All you need for that is to run dhcpd on the server machine.

--
I told you this was going to happen.

.

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