Geeks and IT experts around the world know the meaning of 127.0.0.1, but many may not know why this address exists and why it is associated with localhost . Today's question to answer is therefore: what is 127.0.0.1 "> guide to modify the hosts file, you could also change this association by writing a different name or by completely eliminating the name localhost (but there is no reason to do so).
127 is the last number of a class A network with a Subnet Mask with the value 255.0.0.0 .
127.0.0.1 is the first address assignable in the subnet because 127.0.0.0 cannot be used.
127 is the only important number and in fact addresses like 127.1.1.1 are equivalent to 127.0.0.1.
The class A network number 127 has a " loopback " function which makes the sent packets go back to the sender.
It might have made more sense to choose 1.0.0.0 for this loopback, but it was already busy.
All this to say that 127.0.0.1 is the internal network address of the computer itself .
Being always "himself", it is not possible that a virus comes from this address (unless your computer is already infected) nor that you can "enter" into another PC by looking for it on the net with this address.
127.0.0.1 is the internal computer address for IPv4 networks while in IPv6 the address is the number 0: 0: 0: 0: 0: 0: 0: 1 .
