The “Big Internet Crunch” or “out of IP addresses, again”

The Big Problem:  IP Address Exhaustion (running out of IP addresses)

We’re closing in on the point at which we will have exhausted all the IP addresses on the Internet. This problem of IP addresses running out (IP address exhaustion) has been a rising concern for as long as I’ve been an Internet professional, and that’s about 15 years.  Currently, the Internet is built on top of Internet Protocol version 4 (IPv4) which provides a grand total of ~4.29 billion addresses.  Back in the 70’s when there were just a few dozen computers, 4.29 billion addresses sounded like a lot of space.

Oh, so what the heck is an IP address, you ask?

What are IP Addresses?

IP addresses are composed of four decimal numbers that range from 0 – 255 separated by dots. This is called ‘dotted quad notation’.  An IP address looks something like this:

204.129.16.10

I warned you things were going to get geeky…

Each computer connected to a network must have a unique IP address. IP addresses provide the same function as a public phone number.  IP addresses allow two computers connect to each other across a network, or the Internet by having one globally unique set of IP addresses for all systems connected to the Internet.  Internet Protocol (IP) was designed back when there were very few (a couple dozen or less) computers with Internet access, so a lot of IP addresses were set aside for ‘special use’.  That means that the total number of usable IP addresses is a lot smaller than the total 4.29 billion number.

Take, for example, the ‘loopback’ address range (127.0.0.0 through 127.255.255.255) which is reserved so that all computers can check their internal networking functions. Only one (1) IP address in the range is used frequently: 127.0.0.1, but every computer MUST have it because that’s the way Internet Protocol and the software that makes Internet Protocol work were designed.  So, roughly 16.7 million (minus one) IP addresses can never be used. Then there are all the Private IP Addresses and Multicast addresses and other reserved IP addresses, leaving us with quite a bit less than the 4.29 billion IP addresses.

So how many IP addressesare unusable?

Pages: 1 2 3 4