How does loopback address work?

Replies

• 

  Abhishek Rawal

  It is theoretically said that, loopback address is connected to "Loopback Interface" which is a virtual Network device, so it's not possible of transmission of packets.
  No packets or data bytes goes out of your system, it is bounded to your system.
  
  As far I know, Loopback interface (lo) is usually used to test client-server application in which both client & server are running on same machine.
  Loopback Interface Network Device due to loopback address shows "always connected" thus testing is possible.
• 

  durga ch

  A typical example where loopback IP is used is - to test the TCP IP stack in a specific machine.
  Aka, when you ping an IP address, x.y.z.a , you are trying to reach the IP over a specific set of network.
  When you are trying to access 127.0.0.1, you are just trying to access the local machine, Also its not a physical NIC card or an interface.
  As per primitive internet standards (classfull addressing )Packets destined to 127.0.0.1 are not supposed to leave a specific network and is specifically reserved for localhost purposes