IP and its properties address space subnetting with real time example

IP and its properties address space subnetting with real time example

What is IP and its properties

“IP” stands for Internet Protocol where data is sent by which the method or protocol from one computer to another.  Actually, each computer on the Internet has at least one IP address that uniquely identifies it from all other computers on the Internet. An IP address is a unique global address for a network interface.

IP is an real life example of the postal system. It allows you to address a package and drop it in the system, but there’s no direct link between you and the recipient. TCP/IP, in contrast, creates a connection between two hosts, so that they can send messages back and forth for a period of time.

TCP is one of the main protocols in TCP/IP networks. Whereas the IP protocol deals only with packets, TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent.

Two (2) IP addressing standards are in use today. The IPv4 standard is most familiar to people and supported everywhere on the Internet, but the newer IPv6 standard is gradually replacing it.

  • IPv4 addresses consist of four (4) bytes (32 bits)
  • IPv6 addresses are sixteen (16) bytes (128 bits) long.

IP Address space

An IPv4 address is a 32-bit or  4 byte address that uniquely and universally defines the connection of a device (for example, a computer or a router) to the Internet.

An IPv4 address consists of four numbers, with a single dot (.) separating each number or set of digits.

Each of the four numbers can range from 0 to 255.

An address space is the total number of addresses used by the protocol. If a protocol uses N bits to define an address, the address space is  2N  because each bit can have two different values (0 or 1) and N bits can have 2N  values.

IPv4 uses 32-bit addresses, which means that the address space is 232  or 4,294,967,296 (more than 4 billion).

  • There are two prevalent notations to show an IPv4 address:

(1) Binary notation and

(2) Dotted decimal notation.

Binary Notation:

01110101   10010101   00011101   00000010

Dotted-Decimal Notation:   117.  149.  29.  2

Classful Addressing

IPv4 addressing, at its inception, used the concept of classes. This architecture is called classful addressing. In classful addressing, the address space is divided into five classes: A, B, C, D, and E.

Class Binary Decimal
A 0 0-127
B 1o 128-191
C 110 192-223
D 1110 224-239
E 1111 240-255



Class Start address End Address




The first byte is 193 (between 192 and 223); the class is C.


The first byte is 14 (between 0 and 127); the class is A.

In classful addressing, an IP address of class A, B and C is divided into two parts : Netid and Hostid.

The netid and hostid are of varying lengths that is varies on depending on the class of the address.

Netid(n): The part of an IP address that identifies the network.

Hostid(32-n): The part of an IP address that identifies a host in a network.

Class Net Id Host Id Start address End Address
A 8 24
B 16 16 191. 255.255.255
C 24 8 223. 255.255.255
D Not define 239. 255.255.255
E Not define 255. 255.255.255

Class A address

  • If the first decimal number in IP address is 0 to 127, then it is a class A address.
  • Class A IP addresses use the 1st 8 bits (1st Octet) to designate the Network address.
  • The 1st bit which is always a 0, is used to indicate the address as a Class A address & the remaining 7 bits are used to designate the Network.
  • The other 3 octets contain the Host address.
  • There are 128 (27) Class A Network Addresses, but because addresses with all zeros aren’t used & address 127 is a special purpose address, 126 Class A Networks are available.
  • formula to compute the number of hosts available in any of the class addresses, where “n” represents the number of bits in the host portion:
  • (2n – 2) = Number of available hosts
  • For a Class A network, there are:
  • 224 – 2 or 16,777,214 hosts.
  • Half of all IP addresses are Class A addresses.
  • You can use the same formula to determine the number of Networks in an address class.
  • , a Class A address uses 7 bits to designate the network, so (27 – 2) = 126 or there can be 126 Class A Networks.

Class B IP Addresses


  • If the first decimal number in IP address is 128 to 191, then it is a class B address.
  • Class B addresses use the 1st 16 bits (two octets) for the Network address.
  • The last 2 octets are used for the Host address.
  • The 1st 2 bit, which are always 10, designate the address as a Class B address & 14 bits are used to designate the Network. This leaves 16 bits (two octets) to designate the Hosts.
  • So how many Class B Networks can there be?

Using our formula, (214 – 2), there can be 16,382 Class B Networks & each Network can have (216 – 2) Hosts, or 65,534 Hosts



Class C IP address

  • If the first three bits of the address are 1 1 0, it is a class C network address.
  • The first three (3) bits are class identifiers.
  • The next 21 bits are for the network address.
  • The last eight (8) bits  identify the host.
  • There are millions of class C network numbers.
  • However, each class C network can have 254 hosts.
Class Number of Blocks/ Networks Block size/ Address per block Start address End Address Application
A 128(27) 16,777,216(224) Unicast
B 16384(214) 65536(216) 191. 255.255.255 Unicast
C 2097152(221) 256(28) 223. 255.255.255 Unicast
D 239. 255.255.255 Multicast
E 255. 255.255.255 Multicast



the form /n where n can be 8, 16, or 24 in classful addressing. This notation is also called slash notation or Classless Interdomain Routing (CIDR) notation.

  • the length of the netid and hostid (in bits) is predetermined in classful addressing, we can also use a mask.
  • Default Mask:
Class  Dotted-Decimal Mask
A /8


B /16


C /24



The next article give example of subnetting, Now do practice with blog Subnetting with real time example

TCP and UDP concept with real example in computer network.

TCP and UDP concept with real example in computer network.

TCP and UDP overview

TCP and UDP or TCP over IP or TCP/IP both are protocols. They are the transport layer protocol. TCP is a connection-oriented protocol, on the other hand UDP is a connectionless protocol. Both of them are protocols used for sending bits of data. This is known as packets over the Internet. 

They both build on top of the Internet protocol. TCP and UDP are not the only protocols that work on top of IP. Yet, they are the most widely used. Besides, whether you are sending a packet via TCP or UDP, that packet is sent to an IP address. These packets are pickled correspondingly, as they are accelerated from your computer to intermediary routers and on to the end point. The widely used term known as “TCP/IP” mean as to TCP over IP. UDP over IP could just as well be referred to as “UDP/IP”, but this is not a common term.


TCP stands for Transmission Control Protocol. 

TCP Communication between source to destination computer:

When you want to load a web page, your computer sends TCP packets to the web server’s address. During this asking it to send the web page to you. The web server responds by sending a stream of TCP packets. This is your web browser sews up together to form the web page and display it to you.

When you click a link, sign in, post, or a comment, or do anything else, your web browser sends TCP packets to the server. In additionally, the server sends TCP packets back. TCP is not just one way communication. The remote system sends packets back to acknowledge it is received your packets.

TCP guarantees the recipient will receive the packets accordingly by numbering them. The recipient sends messages back to the sender saying it received the messages. If the sender does not get a correct response, it will resend the packets. This process is use to ensure the recipient received them.

Packets are also checked for errors. This reliability is that packets sent with TCP are tracked so no data is lost or corrupted in transit. This is why file downloads do not become corrupted even so there are network hiccups. If the recipient is completely offline, your computer will give up. Additionally you will see an error message saying it cannot communicate with the remote host.



UDP stands a datagram is the same thing as a packet of information. The UDP protocol works similarly to TCP, though it tosses all the error-checking stuff out. All the back-and-forth communication and deliverability guarantees slow things down.

UDP Communication between source to destination computer:

When using UDP, packets are just sent to the recipient. The sender will not wait to make sure the recipient received the packet; it will just continue sending the next packets. If you are the recipient and you miss some UDP packets, you cannot ask for those packets again. There is no guarantee you are getting all the packets and there is no way to ask for a packet again if you miss it. But losing all this overhead means the computers can communicate more quickly. UDP is used when speed is desirable and error correction is not necessary. For instance, it is frequently used for live broadcasts and online games.

TCP vs UDP or Difference between TCP and UDP protocol

TCP(Transmission Control Protocol)

  • TCP establishes connection between the computers before transmitting the data
  • Connection Oriented type protocol
  • Speed is slow
  • Highly Reliable
  • Header size is 20Bytes
  • It takes acknowledgement of data and has the ability to retransmit, if the user requests.

UDP(User Datagram Protocol)

  • UDP stands the data directly to the destination computer without checking the system is ready or not.
  • Connection type is connectionless
  • Fast in speed
  • Unreliable
  • Header is 8Bytes
  • Neither it takes acknowledgement nor it retransmits the lost data.