R3303-HP 6600/HSR6600 Routers Interface Configuration Guide

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Configuring a null interface
Introduction
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.
Only one null interface, Null 0, is supported on your device. You cannot remove or create a null
interface.
Configuration procedure
To enter null interface view:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter null interface view.
interface null 0
The Null 0 interface is the default null interface on your
device. It cannot be manually created or removed.
3. Set the interface
description.
description text
Optional.
By default, the description of a null interface is interface
name Interface.
4. Set the intended
bandwidth for the null
interface.
bandwidth
bandwidth-value
Optional.
Displaying and maintaining loopback and null
interfaces
Task Command Remarks
Display information about
loopback interfaces.
display interface [ loopback ] [ brief [ down ] ] [ |
{ begin | exclude | include } regular-expression ]
display interface loopback interface-number [ brief
[ description ] ] [ | { begin | exclude | include }
regular-expression ]
Available in any view.