Subnet mask

IP Addressing Crash Course

Do you understand the difference between classless and classful IP addressing? Can you explain what is different in IPv6 from IPv4 and why businesses or individuals should care? How about calculating a subnet mask- or determining the total possible IP addresses based on the subnet mask?

I had a mental block for years on the subnet mask thing. I just could not seem to understand how to do the math either way- either to determine the subnet mask based on the address space I wanted, or to determine the number of available addresses from the subnet mask. Then one day I had an epiphany and what was confusing suddenly made sense. You don’t have to wait for an epiphany though. TechTarget’s SearchNetworking site has a free crash course in IP addressing that will have you understanding that CIDR is different than the cider you drink and otherwise fluent in all things IP. Check it out here- Crash Course: IP addressing and subnetting fundamentals.