Operation Manual – IP Address and Performance OptimizationH3C S5100-SI/EI Series Ethernet Switches Chapter 1 IP Addressing Configuration1-41.2 Configuring IP AddressesS5100-SI/EI Series Ethernet Switches support assigning IP addresses to loopbackinterfaces and VLAN interfaces.A loopback interface is a virtual interface. The physical layer state and link layerprotocols of a loopback interface are always up unless the loopback interface ismanually shut down. A loopback interface can be configured with an IP address, sorouting protocols can be enabled on a loopback interface, and a loopback interface iscapable of sending and receiving routing protocol packets.Each VLAN needs an IP address so that it can be addressed. For more informationabout VLAN interfaces, refer to VLAN Operation in this manual.Besides directly assigning an IP address to a VLAN interface, you may configure aVLAN interface to obtain an IP address through BOOTP or DHCP as alternatives. If youchange the way an interface obtains an IP address, from manual assignment toBOOTP for example, the IP address obtained from BOOTP will overwrite the old onemanually assigned.Note:This chapter only covers how to assign an IP address manually. For the other twoapproaches, refer to the part discussing DHCP.You may assign an interface multiple IP addresses, one primary and multiplesecondaries, to connect multiple logical subnets on the same physical subnet.Follow these steps to configure an IP address for an interface:To do… Use the command… RemarksEnter system view system-view ––Enter interface view interface interface-typeinterface-number ––Assign an IP address tothe Interfaceip address ip-address{ mask | mask-length }[ sub ]RequiredNo IP address is assignedby default.
