Quand Internet est en panne, Active Directory l'est aussi ?

[ForumBot]

I am setting up a business server for a small office use with 5 users / 5 devices or so. Nothing elaborate here.

I've set up a SINGLE Lenovo TS440 server (single NIC) with Windows Server 2012 R2 Essentials. Step by step via install and wizards. No secondary domain controller. I will look into other secondary solutions when I can. I do not want to purchase another server, but I do understand the importance of it.

I set up a domain administrator account which I use for all the workstations and the server during this setup process. Users will not have admin privs, and no local accounts will be on the workstations so they cannot get into workstation without server authentication.

We have a Comcast Business router (CISCO DC3939B with wifi) with a dynamic external IP that hardly ever changes. We also have a TrendNet switch, TEG S80g.

The coax cable internet comes in to the router then router to switch.

The server and about 3 workstations and 2 devices feed in to the switch, and there are a couple wireless devices.

My problem is that after testing the system by removing power to the router and turning off the internet, the workstations can no longer authenticate correctly. Everything works fine with internet available, but I need to make sure that the workstations can still communicate with each other and the server when the internet goes down. I guess I need this WSE 2012 R2 server network to work as if there wasn't internet access to begin with.

Does this maybe have something to do with the router doing DHCP? I am not sure if DHCP can be disabled in the router.

The errors I get when the workstations try to connect to other workstations is that they require the username and pw again, and sometimes they fail to connect. The server isn't down, just the internet. At first I was getting a prompt to turn on Network Discovery, which I did (not public, but private), but we still have this AD problem.

If I left any important details out, please let me know and I can round those up.

[ForumBot]

You should have your Small Business Server (Server Essentials) doing DHCP and DNS. SBS will automatically disable its DHCP service when it detects another DHCP server on the LAN. (You can verify this by checking the event logs, there will be DHCP errors, and the service will likely be stopped)

Since your router is likely handing out the ISPs DNS, your computers cannot authenticate when you power it down.

Connect to your Comcast router and turn off DHCP broadcast, and start your DHCP service on your SBS server. If you used the wizards to configure, the issue you are seeing will likely resolve itself.

Edit: If you are unsure who the DHCP server is, do an ipconfig /all on one of the clients to get the DHCP server IP address.