1-11 DHCP OverviewWhen configuring DHCP, go to these sections for information you are interested in:z Introduction to DHCPz DHCP IP Address Assignmentz DHCP Packet Formatz Protocol SpecificationIntroduction to DHCPWith networks getting larger in size and more complicated in structure, lack of available IP addressesbecomes the common situation the network administrators have to face, and network configurationbecomes a tough task for the network administrators. With the emerging of wireless networks and theusing of laptops, the position change of hosts and frequent change of IP addresses also require newtechnology. Dynamic Host Configuration Protocol (DHCP) is developed to solve these issues.DHCP adopts a client/server model, where the DHCP clients send requests to DHCP servers forconfiguration parameters; and the DHCP servers return the corresponding configuration informationsuch as IP addresses to implement dynamic allocation of network resources.A typical DHCP application includes one DHCP server and multiple clients (such as PCs and laptops),as shown in Figure 1-1.Figure 1-1 Typical DHCP applicationDHCP IP Address AssignmentIP Address Assignment PolicyCurrently, DHCP provides the following three IP address assignment policies to meet the requirementsof different clients:z Manual assignment. The administrator configures static IP-to-MAC bindings for some specialclients, such as a WWW server. Then the DHCP server assigns these fixed IP addresses to theclients.
