What Does Loopback Mean?

Loopback is a test signal sent to a network destination in order to diagnose problems. When the signal is received, it is returned to the originator, where any issues found within the loop are detected. The source of the problem can be found and the problem resolved by sending loopback tests to each piece of telephone equipment, one at a time, in succession.


Techopedia Explains Loopback

Loopback describes ways of routing electronic signals, digital data streams or flows of items from the originating facility to a source without intentional modification or processing. This is a method of testing transmission or transportation infrastructure.

Internet protocols also specify loopback networks. The packets that are sent in an IP network with a source address that belongs to a loopback interface may cause trouble for buggy network software. The IP specification dictates that these packets are not to be transmitted outside the host.

Loopback network addresses are also used in multiprotocol label switching trace route error detection, which aims to avoid the delivery of faulty packets to end users.


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Margaret Rouse

Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…