![what is a loopback address what is a loopback address](https://i.imgur.com/1huDjxF.png)
![what is a loopback address what is a loopback address](https://i.stack.imgur.com/kSMzS.png)
Host loopback refers to the fact that no data packet addressed to 127.0.0.1 should ever leave the computer (host), sending it - instead of being sent to the local network or the internet, it simply gets “looped back” on itself, and the computer sending the packet becomes the recipient. RELATED: The Foundation of the Internet: TCP/IP Turns 40 What Is 127.0.0.1ġ27.0.0.1 is a host loopback address. For that, you need a special reserved IP address with some unique properties - 127.0.0.1. Reserved IP addresses, like most internet standards, are established via documents called Requests for Comment, or RFCs.Īs it turns out, it is often useful to have a computer talk to itself instead of another computer. Reserving addresses for specific purposes makes it easy to establish general rules and behaviours for different IP addresses. The successor to IPv4, IPv6, has more than 10^38 addresses available - enough for every grain of sand on Earth, every star in the observable universe, and every atom in every person’s body to each have a unique IP address, with plenty left over.ĭespite the huge number of IP addresses now available, it is convenient to reserve some addresses, or even ranges (usually called blocks) of addresses, for specific purposes to prevent programming conflicts. Internet Protocol Version 4 (IPv4), which have been in use for decades, allows for nearly 4.3 billion such addresses.
![what is a loopback address what is a loopback address](https://i.stack.imgur.com/3BDda.png)
They identify and communicate with each other using IP addresses, which are conceptually similar to phone numbers. The Internet is made up of billions of devices.