708 CHAPTER 57: DHCP C ONFIGURATIONNetwork diagramFigure 166 Network diagram for Option 82 support on DHCP relay configurationConfiguration procedureSuppose the DHCP relay and the DHCP server is reachable to each other. Thefollowing only introduces the configuration on the switch which serves as theDHCP relay.# Enable the DHCP service system-view[SW8800] dhcp enable# Enter the view of the interface on which the DHCP relay function will beenabled. Configure an IP address and a subnet mask for the interface so that itbelongs to the same network segment with the DHCP client[SW8800] interface vlan-interface 100[3Com-vlan-interface 100] ip address 10.110.1.1 255.255.0.0# Enable the DHCP relay function on the interface, and configure an IP address forthe DHCP relay function (this address specifies the location of the DHCP server forthis interface). Enable Option 82 support on DHCP relay and specify the strategyto keep. Specify the mode as 3Com fixed network mode and the system name asthe node identifier.[SW8800] interface vlan-interface 100[3Com-vlan-interface 100 ] dhcp select relay[3Com-vlan-interface 100] ip relay address 202.38.1.2[3Com-vlan-interface 100] dhcp relay information enable[3Com-vlan-interface 100] dhcp relay information strategy keep[3Com-vlan-interface 100] dhcp relay information format verbose[3Com-vlan-interface 100] dhcp relay information format verbose node-identifier sysnameThe configuration of the DHCP server is omitted here.EthernetEthernetInternetDHCP client DHCP clientSwitch ( DHCP relay )10.110.0.0 DHCP server202.38.1.210.110.1.1202.38.0.0202.38.1.1EthernetEthernetInternetDHCP client DHCP client10.110.0.0 202.38.1.210.110.1.1202.38.0.0202.38.1.1EthernetEthernetInternetDHCP client DHCP clientSwitch ( DHCP relay )10.110.0.0 DHCP server202.38.1.210.110.1.1202.38.0.0202.38.1.1EthernetEthernetInternetDHCP client DHCP client10.110.0.0 202.38.1.210.110.1.1202.38.0.0202.38.1.1EthernetEthernetInternetDHCP client DHCP clientSwitch ( DHCP relay )10.110.0.0 DHCP server202.38.1.210.110.1.1202.38.0.0202.38.1.1EthernetEthernetInternetDHCP client DHCP client10.110.0.0 202.38.1.210.110.1.1202.38.0.0202.38.1.1
