What Is IP ADDRESSING (IPv4)
- IPv4 stands for (Internet protocol version 4)
- IPv4 uses 32 binary bits to create a single unique address on the network. An IPv4 address is expressed by four numbers separated by dots. Each number is the decimal (base-10) representation for an eight-digit binary (base-2) number, also called an octet. For example: 172.20.20.1
IPv4 address has been divided into five types of classes.
- Class A
- Class B
- Class C
- Class D
- Class E
Why IPv4 divided as Classes?
The network address divided into 3 “classes” 1. Class-A large, 2. Class-B medium, and 3. Class-C small networks.
The fourth class and fifth class were essentially for “future use.“
*In Future we will discuss about the Subnetting concepts, then we might be came to know why the IPv4 Address has been divided into classes.
IP Address – Class Range
As discussed above the Internet community originally defined five address classes to accommodate networks of varying sizes. TCP/IP supports class A, B, and C addresses assigned to hosts. The class of address defines which bits are used for the network ID and which bits are used for the host ID. It also defines the possible number of networks and the number of hosts per network.
|Class||1st Octet Decimal Range||1st Octet High Order Bits||Network/Host ID (N=Network, H=Host)||Default Subnet Mask||Number of Networks||Hosts per Network (Usable Addresses)|
|A||1 – 126*||0||N.H.H.H||255.0.0.0||126 (27 – 2)||16,777,214 (224 – 2)|
|B||128 – 191||10||N.N.H.H||255.255.0.0||16,382 (214 – 2)||65,534 (216 – 2)|
|C||192 – 223||110||N.N.N.H||255.255.255.0||2,097,150 (221 – 2)||254 (28 – 2)|
|D||224 – 239||1110||Reserved for Multicasting and using in IPv6|
|E||240 – 254||1111||Experimental- used for research|
Private IP Address:
A private IP address is used only in Local Area Network(LAN).
|Class||Private Networks||Subnet Mask||Address Range|
|A||10.0.0.0||255.0.0.0||10.0.0.0 – 10.255.255.255|
|B||172.16.0.0 – 172.31.0.0||255.240.0.0||172.16.0.0 – 172.31.255.255|
|C||192.168.0.0||255.255.0.0||192.168.0.0 – 192.168.255.255|
A loopback address is a type of IP address that is used to test the communication or transportation medium on a local network card and/or for testing network applications. Data packets sent on a loopback address are re-routed back to the originating node without any alteration or modification
- The Class A addresses 127.0.0.0 to 127.255.255.255 is called loopback address and which we cannot be used in our network.Those IP’s are reserved for loopback and diagnostic functions.
- Loopback Interface is User For Device identification — such as Systems, Firewall, Router, etc.
Difference between public and private IPv4 address
|Public IP Address||Private IP Address|
|Using in WAN(wide area network)||Using in LAN(Local area network)|
|Example: We can access the website: www.doubtsclear.com in world wide, public ip:18.104.22.168||Example: Used for office as a unique ID for a single PC , IP: 172.16.17.101 (Assigned to Systems)|
Why IPv4 divided in public and private IP address?
Now a days the single person is using many devices like Laptop,Mobile,Tab etc.. so we cannot provide three unique IP address for accessing those device for a single user, instead to avoid that we have concept called private IP.
- Globally we have only 4,294,967,296 IPv4 public address
Private IPv4 reduce the consuming of public ipv4 address with the help of Network Address Translation (NAT) concept. Will see the NAT concept soon here.