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.

The Book is Here... and Now On Sale!

Searchable, convenient, complete TCP/IP information.
The TCP/IP Guide

Custom Search







Table Of Contents  The TCP/IP Guide
 9  TCP/IP Lower-Layer (Interface, Internet and Transport) Protocols (OSI Layers 2, 3 and 4)
      9  TCP/IP Internet Layer (OSI Network Layer) Protocols
           9  Internet Protocol (IP/IPv4, IPng/IPv6) and IP-Related Protocols (IP NAT, IPSec, Mobile IP)
                9  Internet Protocol Version 4 (IP, IPv4)
                     9  IP Addressing
                          9  IP Addressing Concepts and Issues

Previous Topic/Section
Number of IP Addresses and Multihoming
Previous Page
Pages in Current Topic/Section
1
2
Next Page
IP "Classful" (Conventional) Addressing
Next Topic/Section

IP Address Management and Assignment Methods and Authorities
(Page 1 of 2)

What would happen if you told someone that you lived at 34 Elm Street, and when that person turned onto your road found four different houses with the number “34” on them? They'd probably find your place eventually but wouldn't be too pleased. Neither would you or your mail carrier. J And all of you folks are much smarter than computers. Where I am going with this is that like street addresses, IP addresses must be unique for them to be useful.

The Need for Centralized Registration of IP Addresses

Since IP datagrams are sent only within the confines of the IP internetwork, they must be unique within each internetwork. If you are a company with your own private internetwork, this isn't really a big problem. Whoever is in charge of maintaining the internetwork keeps a list of what numbers have been used where and makes sure that no two devices are given the same address. However, what happens in a public network with many different organizations? Here, it is essential that the IP address space be managed across the organizations to ensure that they use different addresses. It's not feasible to have each organization coordinate its activities with each other one. Therefore, some sort of centralized management authority is required.

At the same time that we need someone to ensure that there are no conflicts in address assignment, we don't want every user of the network to have to go to this central authority every time they need to make a change to their network. It makes more sense to have the authority assign numbers in blocks or chunks to organizations based on the number of devices they want to connect to the network. The organizations can manage those blocks as they see fit, and the authority's job is made easier because it deals in blocks instead of billions of individual addresses and machines.


Previous Topic/Section
Number of IP Addresses and Multihoming
Previous Page
Pages in Current Topic/Section
1
2
Next Page
IP "Classful" (Conventional) Addressing
Next Topic/Section

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!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $



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.