How I am configure DNS Client and server in Redhat Linux 4 in my lab.

I have total 5 computers and they are Lan connected.I want to make one of them server and the others are client.

Please write clearly, your question is very hard to understand.

There are many how-to and configuration guides available through Google. Basically, pick one of your machines, install DNS server on it, and point your other machines to it, for name resolution.

These two pages can get you started:

http://www.linuxhomenetworking.com/w...onfiguring_DNS
http://www.linuxforums.org/forum/lin...t-dns-gui.html

Also, if you're using RedHat Enterprise 4, I'd suggest contacting RedHat support, since you're paying for it. They have documentation in their knowledgebase, which can walk you through it. If you're just using RedHat4 (not enterprise), it's ancient....upgrade to something new.