The loopback address allows for a reliable method of testing the functionality of an Ethernet card and its drivers and software without a physical network. It also allows information technology professionals to test IP software without worrying about broken or corrupted drivers or hardware.

What is loopback address and why it is used?

The IP address 127.0. 0.1 is called a loopback address. Packets sent to this address never reach the network but are looped through the network interface card only. This can be used for diagnostic purposes to verify that the internal path through the TCP/IP protocols is working.

What is the loopback function?

Loopback (also written loop-back) is the routing of electronic signals or digital data streams back to their source without intentional processing or modification. It is primarily a means of testing the communications infrastructure. There are many example applications.