All About IP Address

randi20

Member
Mar 28, 2008
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All About IP Address


What is an IP address ? If you know the answer of this question then networking will be very easy for you.Here i am giving a detailed tutorial on this topic.This tutorial is meant for begineers.Advanced user can refresh their knowledge.


The IP address is a 32-bit number that is unique to your computer. No two systems can have the same IP address. An IP address is similar to the address of your home, which is the method by which other people send mail to you. An IP address works the same way on a TCP/IP network — you will assign the number to your computer, and it is the method other computers use to send information to your computer.


An IP address is made up of four sets of numbers separated by periods. This is called the dotted decimal notation format of the IP address. An example of an IP address in the dotted decimal notation format is
Code:
198.70.26.200
. Each of the four sets of numbers is referred to as an octet (because each octet represents 8 bits of data).

The IP address is made up of a network ID and a host ID:

The network ID is a unique number used only by your network and is the same for all computers on the same network.
For example, in the IP address
Code:
198.70.26.200
, the first three octets
Code:
198.70.26
make up the network ID.

The host ID portion uniquely identifies a computer on the network.
For example, in the IP address
Code:
198.70.26.200
, the last octet
Code:
200
make up the host ID. Only one computer on the
Code:
131.107.26.y
network can have the host ID of
Code:
200
.

There are three major classes of IP addresses: Class A, Class B, and Class C. The different IP address classes support a different total number of workstations on the network. For example, a Class A network (a network using Class A addresses) supports up to 16,777,214 network devices, while a Class B network supports 65,534 network devices, and a Class C network supports only 254 network devices.

Class A
  1. Number of Hosts: - 16,777,214
    First Octet Value:- 1–126
    Octet Summary:- n.h.h.h
Class B
  1. Number of Hosts: - 65,534
    First Octet Value:- 128–191
    Octet Summary:- n.n.h.h
Class C
  1. Number of Hosts: - 254
    First Octet Value:- 192–223
    Octet Summary:- n.n.n.h
Their are also other classes of IP address Class D, Class E but they will be discussed later,may be in some other thread.An IP address class is determined by seeing the value of its first octet.
Any address starting with 127 is illegal because this address is reserved for the loopback address.

Here’s an IP address example: Computer A has an IP address of
Code:
222.22.220.22
and it initiates communication with Computer B, whose IP address is
Code:
222.22.221.23
Are the two workstations on the same network? Looking at the first octet, you can see that the number
Code:
222
is a Class C address, which means that the first three octets make up the network ID, and the last octet is the host ID. Since there is a difference in the first three octets (which is the network ID), these two computers are on different networks.

Another way to tell whether your computer is on the same network as the computer you are trying to communicate with is to look at the subnet mask. The subnet mask is what your computer uses to determine whether the network device it is trying to communicate with is on the same network or not.

If there is a
Code:
255
in the subnet mask, then the corresponding octet in the IP address is part of the network ID. Once the network ID is known, any systems that have the same network ID are considered to be on the same network — otherwise they would have a different network ID.

For example:
IP Address
Code:
145.90.87.213
belongs to Class B and first two octet makes the network id i.e
Code:
145.90
and its subnet mask will be given by
Code:
255.255.0.0
Computers firstly checks the subnet mask of other computers and then compares the octets to start communication.

So this was a little explanation of IP Addressing. Hope you liked it. :P
 
guys im adding a part which is not mentioned in the origianl post

if you correctly look at the post when it defines class A and class B

Class A starts from 1-126
Class B starts from 128–191

and the address classs 127 is not included in that. well that is because 127 range is called the loopback , it is used for the maintanance and testing. there for the are not included.
 

mimi1983

Active member
  • May 2, 2007
    1,087
    0
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    thanks dude...........I was working for a company which promotes b2b Voip calling internationally..........It's based on IP some shit i guess...........

    Anyways thanks for sharing
     

    randi20

    Member
    Mar 28, 2008
    49
    0
    0
    deffa said:
    guys im adding a part which is not mentioned in the origianl post

    if you correctly look at the post when it defines class A and class B

    Class A starts from 1-126
    Class B starts from 128–191

    and the address classs 127 is not included in that. well that is because 127 range is called the loopback , it is used for the maintanance and testing. there for the are not included.

    ela
    11.gif
    thanx deffa

    I 4got 2 put that

    keep it up
    1.gif
     

    picsms

    Member
    May 10, 2008
    148
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    Hey Guys
    This the firsth post im seing in Ela is usefull and great thax bos, im expecting more from you budy

    Keep going
    nice and good thread i ever scean in ELA

    Always root
     

    doordie_lk

    Member
    Dec 27, 2007
    100
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    lk
    machna good post ..........Keep it up ....try to find IPV6 details also...... bco it is nothing to learn it is all about auto configuring.....version...good....