No idea why but our newly-installed server managed to disappear off the network. It's the main clinical server, was installed a few months back and configured. We've been switched to it about ten days ago. Everything was fine.

Nothing changed within the practice but suddenly the software couldn't connect to the server. Tried ipconfig on the server and it gave me its usual fixed IP address. Tried to ping server from my IP address but it didn't work.

Rebooted server and a few mins after it was up and running, I could ping it and the software could see it. Any ideas why it might have disappeared in the first place? Need to stop a potential problem before it buggers everything up.

If you have checked the obvious like cables and that they are all on, then sometimes I found that rebooting the machine that you are on rather than the server helps. Though you could also do that by logging out and then back in before rebooting.

There's a lot of things it could be.
Although I'd be leaning towards the network stack on the server

Nothing was touched/changed IIRC. I think I did a diagram once.

The servers are upstairs and connect to the switches via data sockets in the walls. The switches are behind a locked cupboard so I know nothing was changed. The "incoming" switch box (connected to the wall data sockets) is the same one. The "outgoing" switch box (where you plug a cable into if you want a data socket to be connected to the network) was recently updated - maybe 6 months ago?

It's either an issue with the network stack or the server crapped out processing something and hung all connections.

I'd check to see if any updates applied themselves (or if the nic on the server is set for power saving)

It's rare you can diagnose a fault that's not there any more, but check the event logs.

If it does it again, first try pulling the network lead and plugging it back in. Check what colour lights are on the switch.

The network equivalent of turning it off and on again!

What OS is this "server" running?
What model is it?
What NIC is installed?

Never updated this but all seem fine.

Anyway, now have a different issue with one of the other servers. Two computers basically keep losing connectivity with this server. Rebooting the computers means connection is established and then disappears after a minute. All of the other 20+ computers can see this same server. Nothing (AFAIK) has been changed.

When you say losing connectivity, does that mean that they can ping it for a couple of minutes but then not any more, or they are losing sight of shares that it holds, or is this an application connection etc? The more detail the better.

This server holds the program for appointment booking and for active directory. Boot up and log in and basically the program doesn't load. At the same time, there's a yellow balloon coming up about offline files. If you then look for the server in the network, the icon for it disappears.

At the moment, logging in under the generic name seems to have worked. But some of the computers require personal log on details for windows. Certainly on two of the computers, the same log in details for windows are normally entered. For these two computers, one works fine and the other is the one affected.

hard to know where to start with that. First up, when the comp loses its access to shares under a specific user account, does it just work again if you log in as a domain admin or other user? Can you ping the server by name or by IP?