Operation Manual – DHCPH3C S5600 Series Ethernet Switches Chapter 3 DHCP Relay Agent Configuration3-6Note:z You can configure up to eight DHCP server IP addresses in a DHCP server group.z You can map multiple VLAN interfaces to one DHCP server group. But one VLANinterface can be mapped to only one DHCP server group.z If you execute the dhcp-server groupNo command repeatedly, the newconfiguration overwrites the previous one.z You need to configure the group number specified in the dhcp-server groupNocommand in VLAN interface view by using the command dhcp-server groupNo ipip-address&<1-8> in advance.3.2.4 Configuring DHCP Relay Agent Security FunctionsI. Configuring address checkingAfter relaying an IP address from the DHCP server to a DHCP client, the DHCP relayagent can automatically record the client’s IP-to-MAC binding and generate a dynamicaddress entry. It also supports static bindings, which means you can manuallyconfigure IP-to-MAC bindings on the DHCP relay agent, so that users can accessexternal network using fixed IP addresses.The purpose of the address checking function on DHCP relay agent is to preventunauthorized users from statically configuring IP addresses to access externalnetworks. With this function enabled, a DHCP relay agent inhibits a user fromaccessing external networks if the IP address configured on the user end and the MACaddress of the user end do not match any entries (including the entries dynamicallytracked by the DHCP relay agent and the manually configured static entries) in the useraddress table on the DHCP relay agent.Follow these steps to configure address checking:To do… Use the command… RemarksEnter system view system-view —Create a static IP-to-MACbindingdhcp-security staticip-address mac-addressOptionalNot created by default.Enter interface view interface interface-typeinterface-number —Enable the addresschecking function address-check enable RequiredDisabled by default.
