What is the Exact function of loop back addressWhich is loop back add127.0.0.0 or 127.1.1.1?

Answer 1

The loopback address is 127.0.0.1. It is also called 'localhost'. It's purpose is simple: It's the most rudimentary test for functionality of your NIC (Network Interface Card). For example, if you ping 127.0.0.1 OR ping localhost you'll get a response IF your NIC is enabled, connected to something (physical network or wireless) and working. Problems with localhost pinging usually means a problem with the NIC itself. Google Web Accelerator, Hello, and some other tools take advantage of the loopback address for functionality. They open a port on loopback to internally 'host' web pages. Google Web Accelerator for example, creates a local cache of your web pages, and sets your proxy to the loopback address on a specific port, so that you get the local cache first, giving the illusion of instantaneous loading of the page.