1-2To do… Use the command… RemarksCreate a Loopback interfaceand enter Loopback interfaceviewinterface loopbackinterface-number —Set a description for theloopback interface description textOptionalBy default, the description of aninterface is the interface namefollowed by the “Interface” string.Shut down the loopbackinterface shutdownOptionalA loopback interface is up onbeing created.z The subnet mask of the IP address assigned to a Loopback interface can only be 32 bits inlength.z Parameters such as IP addresses and IP routes can be configured on Loopback interfaces. Referto the IP Services Volume for detailed configurations.Null InterfaceIntroduction to Null InterfaceA null interface is a completely software-based logical interface. A null interface is always up. However,you can neither use it to forward data packets nor configure an IP address or link layer protocol on it.With a null interface specified as the next hop of a static route to a specific network segment, anypackets routed to the network segment are dropped. The null interface provides you a simpler way tofilter packets than ACL. That is, you can filter uninteresting traffic by transmitting it to a null interfaceinstead of applying an ACL.For example, by executing the ip route-static 92.101.0.0 255.255.0.0 null 0 command (whichconfigures a static route leading to null interface 0), you can have all the packets destined to thenetwork segment 92.101.0.0/16 discarded.Currently, only one null interface, that is, Null 0 is supported on your device. You can neither removethis null interface nor create a new one.Configuring Null 0 InterfaceFollow these steps to enter null interface view:To do… Use the command… RemarksEnter system view system-view —
