Please Whitelist This Site?
I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)
If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.
If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on tcpipguide.com". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||tcpipguide.com^$document". Then just click OK.
Thanks for your understanding!
Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide
|
NOTE: Using software to mass-download the site degrades the server and is prohibited. If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.
|
|
|
|
IP Subnet Addressing Overview, Motivation, and Advantages
(Page 1 of 3)
IP addressing was originally designed
around the assumption of a strict two-level
hierarchy for internetworks. The first
level was the network, and the second level the host.
Each organization was usually represented by a single network identifier
that indicated a Class
A, B or C block dedicated to them. Within
that network they had to put all of the devices they wanted to connect
to the public IP network.
The Motivation for Subnet Addressing
It did not take long after the classful
scheme was developed for serious inadequacies in it to be noticed, especially
by larger organizations. The reason is that while dividing a large internetwork
into networks that contain hosts is conceptually simple, it doesn't
always match well the structure of each of the networks that comprises
the internet. A big company with thousands of computers doesn't structure
them as one big whomping physical network. Trying to assign and administer
IP addresses to an organization's entire network without any form of
internal logical structure is very difficult.
Unfortunately, under the original
classful addressing scheme, there was no good solution to
this problem. The most commonly-chosen alternative at the time was to
trade a single large block of addresses such as a Class B for a bunch
of Class Cs. However, this caused additional problems:
- It contributed to the explosion in size of IP
routing tables.
- Every time more address space was needed, the
administrator would have to apply for a new block of addresses.
- Any changes to the internal structure of a company's
network would potentially affect devices and sites outside the organization.
- Keeping track of all those different Class C
networks would be a bit of a headache in its own right.
If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support! |
|
|
Home -
Table Of Contents - Contact Us
The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005
© Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.
|