Glossary

Note: these aren't the definitions you'd find in a book. If that's what you want, then go look in a book. These are they way I would explain the terms to someone. I'd appreciate it if you'd let me know of anything that's misleading or just plain wrong, but I'm not trying to be too strict. Life is tough enough. Sometimes, I may show some sarcasm, though.

Net Mask

A net mask is a 32-bit binary number that consists of a string of 1's followed by a string of 0's. It is sometimes expressed in 'quad-dot' notation, like 255.255.255.0, or simply as the number of consecutive 1's, like /24. It is used to define a sub-net which is separated from all other networks by a router. The netmask indicates which part of the IP address is on the local network, and which must go out through the router. If your ISP assigns you 8 IP addresses, then your netmask will be 255.255.255.248, which means all your IP addresses are the same except for the last 3 bits. Requests for all other IP addresses must go out over the router.