On Thu, 10 Jul 2025 06:57:10 -0400 Greg Wooledge <[email protected]> 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. > > 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. > That came with 100M Ethernet, so there will be extremely little kit around needing a crossover. -- Joe
