2-12 DHCP Server ConfigurationWhen configuring the DHCP server, go to these sections for information you are interested in:z Introduction to DHCP Serverz DHCP Server Configuration Task Listz Enabling DHCPz Configuring the Global Address Pool Based DHCP Serverz Configuring the Interface Address Pool Based DHCP Serverz Configuring DHCP Server Security Functionsz Configuring DHCP Accounting Functionsz Enabling the DHCP Server to Process Option 82z Displaying and Maintaining the DHCP Serverz DHCP Server Configuration Examplesz Troubleshooting a DHCP ServerCurrently, the interface-related DHCP server configurations can only be made on VLAN interfaces.Introduction to DHCP ServerUsage of DHCP ServerGenerally, DHCP servers are used in the following networks to assign IP addresses:z Large-sized networks, where manual configuration method bears heavy load and is difficult tomanage the whole network in centralized way.z Networks where the number of available IP addresses is less than that of the hosts. In this type ofnetworks, IP addresses are not enough for all the hosts to obtain a fixed IP address, and thenumber of on-line users is limited (such is the case in an ISP network). In these networks, a greatnumber of hosts must dynamically obtain IP addresses through DHCP.z Networks where only a few hosts need fixed IP addresses and most hosts do not need fixed IPaddresses.DHCP Address PoolA DHCP address pool holds the IP addresses to be assigned to DHCP clients. When a DHCP serverreceives a DHCP request from a DHCP client, it selects an address pool depending on theconfiguration, picks an IP address from the pool and sends the IP address and other relatedparameters (such as the IP address of the DNS server, and the lease time of the IP address) to theDHCP client.
