I couldn´t find a specific answer for my question so here it goes: We have a local network with 5 computers and a server running Windows Server 2003. The network was working properly but it seems that the server rebooted and we had to give a static DNS address to each workstation, otherwise they connect to the router 192.168.1.1 and are unable to access the local network or the Internet. So my question is, how do you set up the server so that each workstation uses the server´s IP as primary DNS automatically? Or is it better to configure each client with a static DNS? Thanks in advance.
First, open services (WIndows Key + R, services.msc, Hit enter) and check that 'DHCP Server' is running and set to automatic, if not, right click and select start. While your there restart the DNS Server service.
Secondly, if you are still getting your Router's DNS, log in to your router and ensure DHCP is disabled - you router may have been reset and this may have enabled DHCP which is causing all these problems.
Third, Open DHCP (Start > Administrative Tools > DHCP), Expand your server, you should then see a folder with 'scope' in the name, if not your DHCP needs to be configured (last resort), expand the scope, then select Scope options, it is in this that you will see the IP address of the '006 DNS server'. If it is missing, right click and select configure options, scoroll down to 006 DNS Servers and enter the name or (preferably) the IP address of your DNS server.
I'm 90% sure it'll be your router was reset.
I also thoroughly recommend you migrate from your Server 2003 machine to a new OS and new hardware if it is older than 4 years old as Server 2003 reached end of life on 08/04/2014 along with Windows XP and Office 2003.
Lastly, this may be more suited to ServerFault rather than StackOverflow (same family of websites)