Simple explanation of subnetting and masking?

rhalkyard · ‎08-12-2003

Does anyone have a simple explanation of how to do subnetting and masking of IP addresses? I am having a hard time explaining it to my high school students and all of the resources I have found are still too complicated. To misquote Denzel Washington in Philadelphia, "explain it to me like I was a 2 year old." - Thanks

rsissons · ‎08-12-2003

Try the following URL

http://www.ralphb.net/IPSubnet/index.html

konigl · ‎08-13-2003

Not sure if you've seen this one, but there's a pretty popular document floating around the Internet called "Understanding IP Addressing: Everything You Ever Wanted To Know". It was written by Chuck Semeria of 3Com back in 1996. Was originally available as three PDF files, here's some links to copies of the original:

http://blinky-lights.org/networking/3com-subnetting-a.pdf

http://blinky-lights.org/networking/3com-subnetting-b.pdf

http://blinky-lights.org/networking/3com-subnetting-c.pdf

If you do a google.com search for the terms "everything chuck semeria" without the quotes, you'll find a number of sites with either the HTML version or the PDFs.

It is interesting to note that 3Com's site has a sanitized version, with their newer ringed logo on it AND NO CREDIT TO THE AUTHOR of this classic. Granted, he wrote as an employee of theirs, so they're probably entitled to keep his work as their own. But to not credit him after having his name on the original document for so long, well, that's just wrong. Like so many other things about 3Com... (don't get me started!) Probably a sign that he no longer works for them...