(DNS) server. Using DHCP, a network administrator can avoid hands- on configuration of individual computers through complex and confusing setup applications. Instead, those computers can obtain all required config- uration parameters automatically, without manual intervention, from a centrally managed DHCP server. The DHCP breaks the human/machine association by providing automatic addressing/readdressing for mobile hosts, as shown in Figure 4-14. When a client joins the network, it sends a request for an IP address to the DHCP server, which assigns host configu- ration information to this client from a pool of dynamic addresses. By dynamically assigning the IP address and configuration information to net- worked devices, DHCP reduces the administrative burden of manually con- figuring computers for network use. How the Protocol Works (Basic) In its simplest form, the client sends a request for a server (optionally, with its suggested IP address). The server responds with an available IP address. Next, the client sends a request to the selected server for its con- figuration options. Finally, the server responds with the client's committed How can I find an IP @ ?? Figure 4-14 DHCP in action. Internet IP Backbone Network~ I can use this address: 192.168.5.25 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Function of GPRS Elements Chapter 4 IP address along with other options such as its net mask. If a router exists between the client and the server, the router should use a BOOTP for- warding agent to get the request from the client to the server and back. Computer networks always seem to be changing. New devices (PCs, printers, and SO on) must be attached, old devices disconnected, new branches added, mobile workers hosted, and temporary employees accom- modated; all of these changes can happen every day. Managing all that change can prove 