Please help!!!

Suppose we want to design a media server that holds the index information about what media contents each client machine has in a LAN (i.e. broadcast domain). When a new machine moves to a LAN, it will first contact the media server to upload and download the index information of this machine and of all the other machines in this LAN. The problem is that client machine does not know the IP address of the media server (note that the IP address of such a server in a LAN is different). Design a simple mechanism to solve this problem (Here we assume the new machine has already received an IP address from the DHCP server serving this LAN).