Please check some reasoning regarding minimal networks

[JonJ678]

I *think* you need basically nothing to make a network work. Set static IPs and plug everything into a switch, right?

A modem connects this to the wider world. Something needs to do NAT, if using ipv4. This is usually the same box as the modem, but doesn't need to be. Modem -> NAT device -> switch works fine. Is a "router" exactly the same thing as the NAT device?

Beyond that you can have dhcp, name resolution and so forth. I don't think this needs to be on the same box as anything listed so far.

Am I right in thinking that NAT is all you need to connect a switch to the internet, via a modem?

Thank you for any clarity you might be able to bring to my thoughts.

 

[JonJ678]

It's at home - largely for educational purposes. I've got a few of the all-in-one black box things lying around and set up a two-nic linux box as a firewall/router a year ago. I think it's worth spending some time learning what the black box is doing - the expectation is that it does some important things and a load of extra fluff of dubious value.

For a local network, without any connection to the internet, is static IPs and a switch sufficient? I think it should be, with DHCP (and local DNS) as conveniences.

In the distant past I can remember connecting a single computer directly to a simple adsl modem, so I believe connecting a single computer to the internet doesn't require network address translation. NAT is a means of hiding n machines behind one external IP, which I think is therefore the only requirement to get a group of machines online (via a modem).

If those two premises are correct, then I can move on to more interesting networking ideas (I'm gradually building up the knowledge required to specify a small cluster). Cheers