How many computers are on the internet (order of magnitude)?
Nobody knows quite how many there are, though there has to be more than just a few million. The problem with more and more computers connecting to the Internet is that as more devices (cable modems, ADSL router etc) require a permanent, fixed IP address (basically a unique “address” for each computer, so that one computer on the internet can route its communications to another PC instead of it just floating about in the ether). The existing IP address scheme, IPv4 (a number with four decimal points in, with each group of numbers between the decimal point having a maximum of 3 numbers, up to the value of 255 – eg. 192.168.1.20), was thought up over 20 years ago, and is beginning to show its age. It gives us a maximum of 4.2 billion useable addresses. This is why IPv6 is beginning to rear its head (a new, fresh update of the IP scheme, which uses 128 digit IP addresses instead of the 32 digit ones that the existing IPv4 uses). I quote, from www.crt.net.au/etopics/ip.htm (because it says
