H3C Technologies H3C SecPath F1000-E - Manual (Page 14)

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Configuring a Loopback Interface
Follow these steps to configure a loopback interface:
To do… Use the command… Remarks
Enter system view system-view —
Create a Loopback interface and
enter Loopback interface view interface loopback
interface-number
—
Set a description for the loopback
interface
description text
Optional
By default, the description of an
interface is the interface name
followed by the “Interface” string.
Shut down the loopback interface shutdown
Optional
By default, a loopback interface is up
once created.
NOTE:
Parameters such as IP addresses and IP routes can be configured on Loopback interfaces. Refer to the IP
Services Volume for detailed configurations.
Null Interface
Introduction to Null Interface
A null interface is a completely software-based logical interface, and is always up. However, you
cannot use it to forward data packets or 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, any packets routed to
the network segment are dropped. The null interface provides a simpler way to filter packets than ACL.
You can filter uninteresting traffic by transmitting it to a null interface instead of applying an ACL.
For example, by executing the ip route-static 92.101.0.0 255.255.0.0 null 0 command (which
configures a static route leading to null interface 0), you can have all the packets destined to the
network segment 92.101.0.0/16 discarded.
Currently, only one null interface, interface Null 0, is supported on your device. You cannot remove or
create a null interface.
Configuring Null 0 Interface
Follow these steps to enter null interface view:
To do… Use the command… Remarks
Enter system view system-view —