Network Config Calculator

http://www.subnet-calculator.com/cidr.php

IP Subnetting

http://www.ralphb.net/IPSubnet/class_a.html - CIDR /8

http://www.ralphb.net/IPSubnet/class_b.html - CIDR /16

http://www.ralphb.net/IPSubnet/class_c.html - CIDR /24

IPv6 > IPv4

http://www.metro.co.uk/tech/847019-internet-will-soon-run-out-of-addresses

While this has been known for quite a while by most IT Professionals, it's not really something you would expect to be in a circular like the Metro whose core audience is not technical. Maybe a move to finally get things moving over to IPv6, but by who? Government, IT industry, or tech companies who can hope to gain by the sudden interest in IPv6? Who knows...