Loopback address
127
127.0.0.1 is the loopback address in IP.... or in the (slightly modified) words of Dorthy Gale when she returned from Oz "There's no place like 127.0.0.1"
Local loopback address
The loopback address for each machine is 127.0.0.1, regardless of how many machines are on the network.
127.0.0.1
In IPv4, the loopback address is 127.0.0.1. In IPv6 it is ::1.
host to all
11111111
The usual loopback address is 127.0.0.1 (but any address between 127.0.0.0 and 127.255.255.255 can be assigned to it) The address is also known as http://localhost/. In order to test the connection however a server would have to be installed. Apache is an example of a web based software server.
In a mobile network, a switch's loopback address is a configured logical address not associated with a physical interface. It's useful for routing as it's always up and operational unless otherwise manually brought down. Whereas a physical ip address can lose routing if the interface goes down or if it's handling significant amounts of traffic.
ping 127.0.0.1 CompTIA A+ page 972