On 2025-07-10 04:57, Greg Wooledge wrote: > On Wed, Jul 09, 2025 at 23:23:29 -0700, David Christensen wrote: >> On 7/9/25 22:14, Rick Macdonald wrote: >>> In 30 years I've never seen an isolated network. May I ask how this >>> might be done? >> Assuming an Internet gateway with 4 LAN ports and Wi-Fi, and a server with 1 >> LAN port, turn off everything except the gateway, connect the server LAN >> port to a gateway a LAN port (via switches, if needed), and boot the server. >> Add wired hosts by connecting their LAN port to a gateway LAN port (via >> switches, if needed). Add Wi-Fi hosts by booting them. > An alternative example (with no Wi-Fi): > > * One switch or hub. Connect to power. > * Two or more computers. Connect to the switch/hub, and to power. > * On each computer, set an appropriate address manually, so they can > talk to each other. > > Use any non-routable IP addressing you like. 192.168.1.* is a common > choice.
OK, this I can understand and do. I had actually typed up this as a "guess", but then erased it thinking it might need something more complicated. > As an even simpler example, if you only have *two* computers, you can > connect them directly to each other, without needing a switch/hub. > Back in the olden days (before gigabit ethernet adapters), you would > have needed a special crossover ethernet cable for this. Now, on modern > devices, you should be able to use a regular ethernet cable. I have an extra switch siting on the shelf, so I'm good. Thanks to all for the continuing help. Rick
