I am having some trouble with my client and server codes , i need to send a mac address to the server and get an ip address in return, i ALSO need to MAINTAIN a list of ip adresses allocated and lease time also is involved in this. Need urgent help, been trying this for weeks Please give more detail.
Do you have IT training? Networking?
What is the make mad model of the RELEVANT equipment?

Do you understand that  mac address does not always result in a persistent IP address?

By server, you mean a remote server over Internet?

It might help if you explain why you need this. There already exist many programs that resolve most network problems. Do you have a real unique problem?

Do you understand Dynamic DNS?
The Wikipedia article is defective, but still useful.
http://en.wikipedia.org/wiki/Dynamic_DNS
Quote

The term is used to describe two different concepts. At the administration levels of the Internet, "dynamic DNS updating" refers to systems that are used to update traditional DNS records without manual editing. These mechanisms are explained in RFC 2136, and USE the TSIG mechanism to provide security.
Another kind of dynamic DNS permits lightweight and immediate updates to its local database, often using a web-based mechanism. It is used to resolve a well-known domain name to an IP address that may change frequently. It provides a persistent ADDRESSING method for devices that change their location or configuration.