Part 23 - What is IP addresses ? ( Introduction and types part 1) - Computer Networking- CCNA

WHAT IS IP ADDRESS ?   

Hello friends my name is Vasu Birla and today we will discuss about the IP address so let’s start.

Ip address is a address through which we can identify a particular system within the network.

IT is a unique identifier. And those systems who follows TCP/IP protocol uses this IP address.

IP structure

IP address is also known as Logical address. IT is made of 32 bit  for example.

11001000  00001010   00010100   00011110 

But generally we see ip address on systems like  172.16.254.1   because it hard to remember that is why these 32 bit kept in grouping and  these 32 bits will be divided in 4 parts and it is in decimal system. We use also dotes between these 4 parts of 32 bits.  These four section also known as Octets.

There is also another address known as Physical address also known as MAC address ( Media access control).  This address is in built on NIC card (Network Interface Card) where we plug the RJ-45 Cable or Ethernet cable. This physical address is also provide unique identification of system within network but it has a limitation that this address works on Layer 2 data link layer  but when you want to get connect two different network in that case only layer 3 devices are used when we need layer 3 address means IP address.

Types of IP address -  there are four methods  for dividing types of ip addresses.

1. Assignment
2. Classes
3. Public and Private IPs
4.  Versions

1.       1. Assignment  -    there are two types of ip address in this method – 

a.      Static IP address -  In this IP address all we do all configuration manually. Basically in small network or on particular server  we can assign ip address manually and it doesn’t change itself  it is fixed ip address until we change again manually. 

b.   Dynamic IP address – Dynamic IP address means  IP addressed are assigned automatically through DHCP server or APIPA  we will discuss about it later.

2.      

2. Classes – There are 2 classes of IP address  Classful and ClassLess

a.       Classful - In classful 5 Classes of IP address  A,B,C,D and E.

                                                               i.      Class A reserved for governments Org or very big organization.
                                                             ii.      Class B reserved for medium companies.
                                                            iii.      Class C reserved for small companies.
                                                           iv.      Class D reserved for Multicasting purpose.
                                                             v.      Class E reserved for future uses or for experimental purpose.

Here is some example of Classful classes  A,B and C

Class A- 35.0.0.0 - Network id – 8 bit      Host address- 24 bit   -   Begins -  1 to 126

Class B – 128.5.0.0-   network id – 16 bit -  Host address – 16 bit  Begins – 128-191

Class C - 192.33.33.0 -   network id – 24 bit – Host address – 8 bit Begins – 192- 223

We can identify class of IP address by its first number  when network is not sub-netted or only in Classful ip address

CLASS A IP address -   Lets have some deep look in class A ip address .

As we know IP address is made of 32 bits ,  and in this 32 bits first bit of IP add will be always Zero 0 remaining 31 bits will be anything  but first bit of Class A IP address will be 0  always.

Class A IP address has only 8 bit network part it means we have only 7 bits to make network part because first bit it 0 – so  by 7 bits we can have only 128 possible address and remaining 24 bits are for hosts.

In the class A 16 million hosts are available per A class network.  16 million 777 thousand 216. But it is impossible to configure 16 m hosts within a single network .

Example of Class A IP address

0nnnnnnn.hhhhhhhh.hhhhhhhh.hhhhhhhh

00000000.00000000.00000000.00000000

                                To

01111111.11111111.11111111.11111111

First bit of class A begins with 0 always then 7 bits is for network id and rest 24 bits for  hosts bits.

Range of ip address is   0.0.0.0  to 127.255.255.255   but  0 and 127 is reserved already for special purposes  .

0.0.0.0          And  0.255.255.255

127.0.0.0    and 127.255.255.255

These Ip addresses are exceptions in Class A IP address .  all 0s range means 0.0.0.0 represents default network or my network  we can not assign this ip add to any host.

And 127.0.0.0  range is also known as loopback address it is used to self testing of network and it helps to troubleshoot NIC (Network Interface card) using ping commend. 

FIRST FIXED BITS FROM EACH CLASS OF IP

So these IPs can not be considered in Class A  so originally  range of class A is  1 to 126.   

Class B IP address

Class B IP address is also consist of 32 bits   first 16 bits of network portion and rest 16 bits are for hosts.

Class B IP address begins with  1 and 0    first two bits always will be 1 and 0 

So here we have only 14 bits for network portion because first two bits 1 and 0 is fixed  so   we have  16384 possible number of networks in Class B.

Remaining 16 bits of hosts  provide us 65536 possible hosts or users.

Example of B class IP add

10nnnnnn.nnnnnnnn.hhhhhhhh.hhhhhhhh

10000000.00000000.00000000.00000000

                To

10111111.11111111.11111111.11111111

Its start with  128.0.0.0  to 191.255.255.255   its range of Class B IP adds.

Except it  there is some exceptions in class B IP adds  its  169.254.x.x    we don’t assign this IP address to any host  because this range is already reserved for APIPA (Automatic Private IP addressing)  this IP adds will be automatically configured by System if there is no DHCP (Dynamic Host Configuration Protocol) service available for user.

Class C IP address

Class C IP address consists of 32 bits  in this first 24 bits are for network portion and remaining 8 bits are for hosts portion. 

Class C IP add are very popular and commonly used by many service providers and by private networks.

In class C ip address  first 3 bits begins with  1,1 and 0  and these bits are fixed.

First 3 bits are 110  these are fixed bits and remaining 21 more bits in network part provide us over 2 million possible class network

And 8 bits of host part provide us only 256 class c host ip addresses.

110nnnnn.nnnnnnnn.nnnnnnnn.hhhhhhhh

11000000.00000000.00000000.00000000

                                To

11011111.11111111.11111111.11111111    

It start with 192.0.0.0 to 223.255.255.255  

Class D IP address 

Class D IP addresses are used for multicasting purposes  and its range is  224.0.0.0 to 239.255.255.255

These IP adds are used for one to many communication. Multicasting is a way through which we can get communicate one to many users.

IT is consist of 32 bits and  first 4 bits are always fixed  these 4 bits are 1110.

IT send message to group of hosts  we can not communicate one to one  means unicasting and one to all means broadcasting.

Example of multicasting like  video conference , live streaming videos only selected group of receivers available.

11100000.00000000.00000000.00000000

                                To

11101111.11111111.11111111.11111111

224.0.0.0    to   239.255.255.255

Some popular Class D IP address used by some special protocols in routers for example –

224.0.0.5  this class D IP is used by OSPF protocol to send hello packets.

224.0.0.6 is also used by OSPF router to send routing information to designated router on  a network segment.

224.0.0.9  this class D IP add is used by  Routing information Protocol version 2 (RIPv2) to send routing information to all RIPv2 aware routers on a network segment.

224.0.0.10 this class D IP add is used by EIGRP routing protocol to send routing info.

224.0.0.18 is used by Virtual Router Redundancy Protocol (VRRP).

Class E IP address

Class E IPs starts with 240.0.0.0 to 255.255.255.255 . These IP adds are used for experimental purposes but there is no description of these experimental purposes  but  some government and bit private organization uses these IP add.

Consist of 32 bits and first 4 bits are fixed these bits are 1111   lets have look of  binary form of This IP

11110000.00000000.00000000.00000000

To

11111111.11111111.11111111.11111111

Means in decimal form  its 240.0.0.0 to 255.255.255.255  

Thanks for reading  please share this blog to your friends and subscribe  in the next part we will discuss about the third method or types or IP address   Public and Private Ip adress ....  ok friends.. good luck for life..... Hare krishna...