H3C Technologies H3C S10500 Series Switches - Manual (Page 31)

20
To do… Use the command… Remarks
Shut down the loopback interface shutdown
Optional
By default, a loopback interface is up.
Restore the default settings for the
loopback interface
default Optional
NOTE:
You can configure settings such as IP addresses and IP routes on loopback interfaces. For more
information, see
Layer 3—IP Services Configuration Guide and Layer 3—IP Routing Configuration Guide.
Configuring the null interface
Introduction to the 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 that leads to null interface 0), you can have all the packets destined to the network segment
92.101.0.0/16 discarded.
Only one null interface, Null 0, is supported on your switch. You cannot remove or create a null interface.
Configuration procedure
Follow these steps to enter null interface view:
To do… Use the command… Remarks
Enter system view system-view —
Enter null interface view interface null 0
Required
The Null 0 interface is the default null interface on
your switch. It cannot be manually created or
removed.
Set the interface
description
description text
Optional
By default, the description of a null interface is
interface name Interface.
Restore the default settings
for the null interface
default Optional