Because IP addresses must match the network IP address, this makes mobile computing impossible without manual changes to the table. With DHCP, there is no fixed, manual correlation between ethernet address and IP address. It is assigned on the fly when the client requests an address. The assigned address is automatically appropriate for the IP network on which the computer is physically residing. Thus, a computer can be moved around at will without manual reconfiguration.
Many computers run servers.
It is undesirable to have to reach a server by its IP address. This presents a problem for mobile computers that change DHCP assigned IP addresses as they move around. Dynamic DNS proposes to solve this problem by integrating DHCP and DNS functionality. Before implementing such a solution two problems must be solved. First the campus IP address space must be flattened to allow proper DHCP operation.