3Com 3031 Command Reference Manual page 237

interface loopback
interface null
Configuration Command of Loopback Interface and Null Interface
For a related command, see interface null.
Example
View status information of Null0 interface.
<3com> display interface null 0
NULL0 current state : UP
Line protocol current state :UP (spoofing)
Physical is NULL DEV
Description : 3Com Routers, NULL0 Interface
The Maximum Transmit Unit is 1500
Internet protocol processing : disabled
5 minutes input rate 0 bytes/sec, 0 packets/sec
5 minutes output rate 0 bytes/sec, 0 packets/sec
0 packets input, 0 bytes, 0 drops
0 packets output, 0 bytes, 0 drops
Syntax
interface loopback number
undo interface loopback number
View
System view
Parameter
number: Number of Loopback interface, ranging from 0 to 1023.
Description
Using the interface loopback command, you can create a Loopback interface or
enter Loopback interface view. Using the undo interface loopback command, you
can delete a specified Loopback interface.
After a Loopback interface is created, it always keeps up state, and bears loopback
feature, so it is often used to improve the reliability of configuration.
For the related command, see display interface loopback.
Example
Create Loopback interface 5.
[3com] interface loopback 5
[3com-LoopBack5]
Syntax
interface null 0
237