Operation Manual – DHCPH3C S3100 Series Ethernet Switches Chapter 1 DHCP Overview1-1Chapter 1 DHCP Overview1.1 Introduction to DHCPWith networks getting larger in size and more complicated in structure, lack of availableIP addresses becomes the common situation the network administrators have to face,and network configuration becomes a tough task for the network administrators. Withthe emerging of wireless networks and the using of laptops, the position change ofhosts and frequent change of IP addresses also require new technology. Dynamic hostconfiguration protocol (DHCP) is developed to solve these issues.DHCP adopts a client/server model, where the DHCP clients send requests to DHCPservers for configuration parameters; and the DHCP servers return the correspondingconfiguration information such as IP addresses to implement dynamic allocation ofnetwork resources.A typical DHCP application includes one DHCP server and multiple clients (such asPCs and laptops), as shown in Figure 1-1.Figure 1-1 Typical DHCP application1.2 DHCP IP Address Assignment1.2.1 IP Address Assignment PolicyCurrently, DHCP provides the following three IP address assignment policies to meetthe requirements of different clients:z Manual assignment. The administrator configures static IP-to-MAC bindings forsome special clients, such as a WWW server. Then the DHCP server assignsthese fixed IP addresses to the clients.z Automatic assignment. The DHCP server assigns IP addresses to DHCP clients.The IP addresses will be occupied by the DHCP clients permanently.
