2-17Note:When an S5600 Ethernet switch works in the interface address pool mode as a DHCP server, the onlygateway address it can assign to a client is the primary IP address of the interface.Enabling the Interface Address Pool Mode on Interface(s)If the DHCP server works in the interface address pool mode, it picks IP addresses from the interfaceaddress pools and assigns them to the DHCP clients. If there is no available IP address in the interfaceaddress pools, the DHCP server picks IP addresses from its global address pool that contains theinterface address pool segment and assigns them to the DHCP clients.Follow these steps to configure interface address pool mode on interface(s):To do… Use the command… RemarksEnter system view system-view —interface interface-typeinterface-numberdhcp select interfaceOn the currentinterfacequitConfigure interfaceaddress pool modeOn multipleinterfaces insystem viewdhcp select interface{ interface interface-typeinterface-number [ tointerface-type interface-number ]| all }RequiredBy default, a DHCPserver assigns the IPaddresses of the globaladdress pool to DHCPclients.You need to configure an IP address for the interface before enabling the interface address pool modeon it.To improve security and avoid malicious attack to the unused sockets, S5600 Ethernet switchesprovide the following functions:z UDP port 67 and UDP port 68 ports used by DHCP are enabled only when DHCP is enabled.z UDP port 67 and UDP port 68 ports are disabled when DHCP is disabled.The corresponding implementation is as follows:z After a DHCP interface address pool is created by executing the dhcp select interface command,UDP port 67 and UDP port 68 ports used by DHCP are enabled.z After a DHCP interface address pool is deleted by executing the undo dhcp select interfacecommand and all other DHCP functions are disabled, UDP port 67 and UDP port 68 ports used byDHCP are disabled accordingly.
