How to install DNS server with simple conf internally

[consistgd]

I need to install and configure DNS server in a LAN just to test some software packadges. I do not want it to be tied to the internet. I need to have some domain names like host1.myoffice, host2.myoffice, host3.myoffice. Is that possible?
Anybody can advise how to do that?
Will that make troubles for the other worstations on the LAN?

[blammo]

Give dnsmasq (http://thekelleys.org.uk/dnsmasq/doc.html) a look see. It will do what you ask and even forward to the real DNS server on your network, so you can resolve outside of your little group of machines. It won't mess with the other machines on the LAN. Even if they are pointing to it and can't resolve the host names, the forwarders will take them to the main server, where they can.

[consistgd]

Give dnsmasq (http://thekelleys.org.uk/dnsmasq/doc.html) a look see. It will do what you ask and even forward to the real DNS server on your network, so you can resolve outside of your little group of machines. It won't mess with the other machines on the LAN. Even if they are pointing to it and can't resolve the host names, the forwarders will take them to the main server, where they can.
Thanks a lot for the reply. I installed and tested it. But not everything worked well.
Here is the situation:
I do not need DHCP. I have all local IP fixed (for the test environment). But I do have DHCP running on this network with Windows 2000 server.
I installed and started dnsmasq on the Red Hat Linux 8.0, computer name redhat80. I defined real DNS servers on this computer. From this computer I can ping all computers on a LAN and on the internet by address and by name.
On other linux machines in the LAN I defined redhat80's IP address as the only DNS server. Some of the Linux machines where mentioned in redhat80's /etc/hosts file and some were not. From all these machines I was able to ping all other machines, mentioned in /etc/hosts on redhat80 by name, the dnsmasq DNS server. So for linux hosts it worked.
On Windows machines on the same LAN I defined redhat80 as DNS server as well. And I was able to ping Internet websites from these Windows (XP and 2000) machines as well as to connect them via browser. So for the Internet it worked.
BUT I was not able to connect any of the Linux machines by name, mentioned in /etc/hosts on redhat80, the DNS server with dnsmasq running.
Something is missed here. Any idea, what?

All the best.
Gregory