Solve software problem quickly Share experience to help others Improve the ability of solving problem
Difference Between Class C & Class D IP Addresses

11/22/2011 02:38 by LindaRodrigues

First answer posted by lainib at 11/22/2011 02:38
Add Your Answer
10~1000 characters in length CAPTCHA:
2 Answers
  • lainib
  • Those who have seen an IP address will remember that it is shown as four numbers each separated by a dot ("."). This is just a way of representing the true address in a form easier for humans to copy. The real address is a 32-digit binary number in the original scheme of the IP address. The address was divided into two parts, a network ID and a host ID. The size of each part varied depending on the class of the address. Class C and Class D are two of the categories explaining where the division of the IP address lies.


    Classful Addressing

    In Classful Addressing, the first part of the IP address is the network ID and the second part is the host ID. Each part takes up a different amount of numbers depending on the class. Class C addresses give the first 24 positions to the network ID and leave eight positions for the host ID. The network ID identifies the network to the outside world. The host ID is a specific computer within that network. Classes A, B and C are allocated to: large networks with many computers (Class A), mid-sized networks (Class B) and small networks with few computers (Class C). Class D addresses are not divided between network ID and host ID. The entire space is used to identify a multicast group. Classes A, B and C enable one-to-one communication, while Class D enables one-to-many communication.


    Class Identification

    Although the first segment of the IP address in Classes A, B and C identifies the network ID, the first four bits actually identify the class. If the first bit is a zero, the address is Class A, if the address starts with "10" it is Class B. Class C addresses all begin with "110"and Class D addresses begin with "1110." This leaves Class E with all addresses starting with "1111." Half of all IP addresses under this scheme are Class A addresses, a quarter of all addresses are Class B, an eighth of all addresses are Class C, and Class D and Class E each have one-sixteenth of all addresses. Class E addresses are reserved for research. This scheme classifies all addresses between and as Class C and all addresses between and as Class D.



    Class D addresses operate differently from the conventional usage of Classes A to C. A multicast is like an opt-in mailing list. Each IP address references a group. Any computer wishing to be a part of that group sends a registration message to that IP address. Any data message sent to that IP address is forwarded to all the IP addresses registered in that group.


    Classless Addressing

    Classful Addressing wasted a lot of addresses. It kept half of all IP addresses reserved for large companies, when the uptake of the Internet by the general public created large demand for Class C addresses. The class system was scrapped in 1993 with the introduction of "Classless" IP addresses. This effectively merges Classes A, B and C, although the Class D range of addresses for IP multicasting still exists.

  • Was this answer helpful? 00 · 11/22/2011 02:38
  • Anonymous user
  • I don't Know
  • Was this answer helpful? 00 · 01/01/2013 12:42
Add Your Answer
10~1000 characters in length CAPTCHA:
Related Questions
Q:How to Use Task Tracking Software

A: Right click on your Windows task bar and click "Task Manager" or "Start Task Manager," depending on your version of Windows. Click "Applic...(more)

Q:Driver Testing Software

A:Automated testing software for devices and drivers are available for a broad spectrum of hardware and software. Developers use these utiliti...(more)

Q:Software for Expense Tracking

A:Expense tracking software can be a very useful tool for budgeting and keeping track of where money is going. Programs have different feature...(more)

Q:How to Calculate Cost Per Impression

A: Determine the number of impressions for the ad. Most ad software tracks the number of times an ad is shown. While most Internet marketing af...(more)

Q:Critical Success Factors in Information Systems

A:Information systems use information technology to support operations, management and decision-making. Essentially, information systems are u...(more)

0 people are following

Ask a question now
Write a title for your question

Social Spy

Remote Visual Real-time Computer Spy Software - See everything in Real-time!
Latest version:1.55
OS:Windows 7/Vista/2003/XP/2000/NT
Total downloads:10,197
Rank:28 in Monitoring Software
Download It

Share with friends

New features is coming

  • 1. Providing high-quality answers to be a verified Q&A expert
  • 2. Ask and answer questions to get Brothersoft credits

Added Successfully!


Are you sure to delete your answer?



Are you sure to choose it as the best answer?



Voted Successfully!


You can't vote for yourself


You can't choose your own answer