Computer Awareness Notes – IP Address
What is an IP Address
Internet Protocol (IP) Address – Just like we have a house address for reaching someone’s house, a computer system on the internet has an IP Address. It is an address through which a computer is identified on a network/internet.
Example of an IP Address– 192.168.1.1
Types of IP Address (Versions)
- Presently two versions of IP Address is in use.
- IPv4 and IPv6 (v denotes version)
Important Points about IPv4
- It is a 32 bit (4 bytes) unique address having an address space of 232
- It has four parts and each part can have values between 0 to 255. Example 255.255.255.255 is a valid IP Address, however, 192.168.256.123 is an invalid IP Adress as the third part (256) is not valid.
- Note that the four parts in this IP address are separated by a dot (.)
- IP addresses are globally managed by Internet Assigned Numbers Authority(IANA) and regional Internet registries(RIR).
- IPv4 was the first version of IP which was deployed for production in the ARPANET in 1983
Subnet Mask– A subnet mask is a 32-bit number used to differentiate the network component of an IP address by dividing the IP address into a network address and host address. Subnet masks are used to design subnetworks, or subnets, that connect local networks
Classes of IP Address
IP Address is divided into 5 classes based on the address range. It is as follows:
| Class | From | To |
| Class A | 1.0.0.0 | 127.255.255.255 |
| Class B | 128.0.0.0 | 191.255.255.255 |
| Class C | 192.0.0.0 | 223.255.255.255 |
| Class D (Reserved for multicast groups.) | 224.0.0.0 | 239.255.255.255 |
| Class E (Reserved for future use, or research and development purposes.) | 240.0.0.0 | 255.255.255.255 |
DHCP- The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on UDP/IP networks whereby a DHCP server dynamically assigns an IP address and other network configuration parameters to each device on a network so they can communicate with other IP networks.
Loopback IP Address: An address that sends outgoing signals back to the same computer for testing. In a TCP/IP network, the loopback IP address is 127.0.0.1, and pinging thisaddress will always return a reply unless the firewall prevents it.
DNS (Domain Name System)– On an interent, every website is associated with a unique IP Address. For example, the IP Address of Google India is 216.58.200.163. SO when you open google, you are actually opening 216.58.200.163. The system/server that performs this task conversion of web names to IP Address is known as Domain Name System (DNS). In simple words, it is the phonebook of the Internet.
Important Points about IPv6
Due to the rise in the number of devices that are connected on the internet the available IP Address on IPv4 (2^32) would soon get exhausted. Hence there was a need for a system of IP Address that could accommodate more devices.
- It is 128-bit address space.
- It has eight 4-character.
- It is in hexadecimal.
- Example: 2001:0db8:0000:0000:0000:ff00:0042:7879
- IPv6 also called IPng (Internet Protocol next generation).
- IPv6 is the successor of IPv4.