Dan York on Twitter: "Nice cheat sheet for #IPv4 subnetting (and a good reminder that if you move to #IPv6 you don't have to worry as much about all these smaller subnets
IPv4 - Subnetting
Subnet Mask Reference Table | Brain Knowledge
Subnet Mask Cheat Sheet - The Cisco Learning Network
IPv4 Subnet Mask Cheat Sheet - Beetle Digital
Subnetting on the 3rd and 4th Octet - examples - FlackBox
Subnet Mask Cheat Sheet - A Tutorial and Thorough Guide to Subnetting!
networking - How exactly is a subnet mask used when determining where to send a packet to? - Super User