A loopback interface is a logical interface that is always Up. A loopback interface is usually used in a loopback test.
Context
According to the TCP/IP protocol suite, the IP addresses on the network segment 127.0.0.0 are loopback addresses. The interfaces that are configured with these addresses are loopback interfaces. During startup, the system automatically creates an interface that uses the loopback address 127.0.0.1 to receive all the packets sent to the local switch.
Procedure
- Create a loopback interface.
- Click Create.
Table 1 describes parameters on the page.
Table 1 Creating a loopback interface Parameter
Description
Loopback interface name
Enters the number of the loopback interface. This parameter is mandatory.
IPv4 address/Mask
Enters the IPv4 address and subnet mask of the loopback interface.
IPv6 address/Prefix length
Enters the IPv6 address (for example, FC00:0:130F:0:0:9C0:876A:130B) and prefix length (ranging from 1 to 128).
You can click
to add an IPv6 address or click 
to delete an IPv6 address.
- Click Create.
- Modify a loopback interface.
- Click a loopback interface name in the loopback interface list to access the corresponding loopback interface modification page.
Table 1 describes parameters on the page.
NOTE: The loopback interface name cannot be modified.
- Click a loopback interface name in the loopback interface list to access the corresponding loopback interface modification page.
- Delete a loopback interface.
- Choose to access the Loopback Interface page.
- Select a record that you want to delete and click Delete. The system asks you whether to delete the record.
- Click OK.
- Update a loopback interface.
- Choose to access the Loopback Interface page.
- Click Refresh.