Configuring The Null Interface; Introduction; Configuration Procedure; Displaying And Maintaining Loopback And Null Interfaces - HP HSR6800 Configuration Manual

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

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:
Step
1. Enter system view.
2. Enter null interface
view.
3. Set the interface
description.
4. Set the intended
bandwidth for the null
interface.
5. Restore the default
settings for the null
interface.
Displaying and maintaining loopback and null
interfaces
Command
system-view
interface null 0
description text
bandwidth bandwidth-value
default
85
Remarks
N/A
The Null 0 interface is the default null interface
on your device. It cannot be manually created
or removed.
Optional.
By default, the description of a null interface is
interface name Interface.
Optional.
Optional.