Operation Manual – DHCPH3C S7500 Series Ethernet Switches Chapter 2 DHCP Server Configuration2-1Chapter 2 DHCP Server ConfigurationWhen configuring DHCP servers, go to these sections for information you areinterested in:z Introduction to DHCP Serverz Global Address Pool-Based DHCP Server Configurationz Interface Address Pool-Based DHCP Server Configurationz DHCP Security Configurationz Displaying and Maintaining a DHCP Serverz DHCP Server Configuration Examplez Troubleshooting a DHCP Server2.1 Introduction to DHCP Server2.1.1 Usage 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 loadand is difficult to manage the whole network in a centralized way.z Networks where the number of available IP addresses is less than that of thehosts. In this type of networks, IP addresses are not enough for all the hosts toobtain a fixed IP address, and the number of on-line users is limited (such is thecase in an ISP network). In these networks, a great number of hosts mustdynamically obtain IP addresses through DHCP.z Networks where only a few hosts need fixed IP addresses and most hosts do notneed fixed IP addresses.2.1.2 DHCP Address PoolA DHCP address pool holds the IP addresses to be assigned to DHCP clients. Whena DHCP server receives a DHCP request from a DHCP client, it selects an addresspool depending on the configuration, picks an IP address from the pool and sends theIP address and other related parameters (such as the IP address of the DNS server,and the lease time of the IP address) to the DHCP client.I. Types of address poolsThe address pools of a DHCP server fall into two types: global address pool andinterface address pool.z A global address pool is created by executing the dhcp server ip-poolcommand in system view. It is valid on the current device.
