January 9th, 2014, 07:42 AM
Internet lost when server down
We have a server 2003 office domain. It connects to the internet via a sonicwall router then out to Charter on a static IP. The gateway is a static IP. When our server with Ad that controls all users is up, we have internet, and when it is down we don't. But, the gateway is set in all workstations, so we are trying to figure out why a workstation can't get out to the internet even when our server is down?
January 10th, 2014, 10:56 AM
If all the workstations and the server feed into the gateway, then you do not lose Internet connectivity. To verify, ping to a physical IP address when the server is up, and when it is down.
Most likely the problem is DNS. You are probably using HDCP to connect, and DHCP is assigning the server as the default DNS server. That server will provide Intranet service for local services, and relay other requests to an outside DNS server. You can always override this default by using your own DNS settings. One would be the local server, and the other and outside DNS server.
January 10th, 2014, 11:03 AM
We actually have in each workstation the IP address of the server and the IP of the gateway, but as soon as the server is down a WS can't see the gateway I'm assuming. I will ping the gateway with the server up and the server down and see what happens. The gateway then looks at the IP settings for our cable modem. How would I override any problem here via a DNS setting? Thanks!
Originally Posted by couttsj
January 11th, 2014, 11:38 AM
If you are using the Windows OS, the Local Area Connection Properties display the current settings. The default settings are:
1. Obtain an IP address automatically
2. Obtain DNS Server address automatically
You can change that and enter your own. If the gateway is one of them, it must support DNS relay to function properly. The DNS used is actually whatever it has in it's settings. If it is set to use your internal server, then obviously both will fail. Although you can theoretically use more than 2 DNS servers, it is not advised, as it can take a long time to time out on all of them on a bad lookup.
If you run a ping test, ping to an outside address. I use one of my ISP's servers that is known to be reliable.
January 11th, 2014, 12:38 PM
OK. Each workstation has the server IP and the gateway IP (which has the ISP settings in it) and actually the ISP settings too, but of course they mean nothing because the gateway is the only way to get to the internet. So what seems to be happening is when the server is down, WS's can't see the gateway, as the gateway is on the network. When the server is down then the network is down. So maybe there IS no way around this behavior?
It's just that it seemed I used to be able to get around this.
January 11th, 2014, 11:20 PM
The local network configuration is determined by the IP address and the netmask. For example, 192.168.1.10/255.255.255.0 defines a network of 254 addresses with the network defined as 192.168.1.0 and 192.168.1.255 used as the broadcast address. When an address is selected outside of the local subnet, it is directed to the gateway. The gateway has 2 network interfaces; one sits on the Local Area Network (LAN), and the other sits on the Wide Area Network (WAN). Normally, all workstations, servers, and gateway LAN reside on the same local network or subnet connected via a switch or hub. It is possible for communication to occur across different subnets, but that would be an unusual setup.
Many offices will use a proxy server to improve performance and control web access. That however has nothing to do with the network setup, but is controlled by the browser settings.