IP address stands for Internet Protocol Address.
when some one asks ur home address for delivery of something ,u gave house number,locality,picode..etc..etc,that is the address by which ur home getting identified. In networking ip address is used to identify computer’s location,also it will used to send data from one computer to other.

casting: sending packet from one host to other host 3 types 1.Unicasting 2.Broadcasting 3.Multicasting

Ip addressing is clasified into two forms.
1.classfull addresing
2.classless addressing system(CIDR)

we know ip address is one of the important element in networking
ip address is used to reach destination computer
when we visit a website say googl.com
the isp is configured us a service called dns
dns will convert domain name into ip address
now ip addresss has 2 parts ,one is network address which is used to reach destination network,host address is used to identify destination host within network,in addition to that destination proceess number (port number) used to reach right process ,for web service server listens on port 80, so our destinatiion port is 80,for well defined ports no need to mention port number.

There are 2 types of connection options in computer networks,One is wired,other one is wireless.
in wired computer network cables are used to connect devices
ethernet is best example for wired coommunicaion
In wireless communication waves are used for communication
ex:wifi
a wireless access point a.k.a router used for wireless communication all devices connected to wifi router for communication

In a wired lan ethernet is most popular

if there are many paths in a big network deciding which way to direct the traffic is done by the switching
switching provides a feel like one-to-one connection

OSI stands for Open System Interconnection,by seeing abbreviation we can tell that it is used to fascilitate communication between systems. it has 7 layers
protocols in each layer goverrns the data commuincation

osi model is just a reference/guideline for network architecure,tcp/ip is the actual model we will use unlike osi refference model tcp/ip model contains 4 layers only all activities is done by protocols at each layer

In a computer so many processes are runs each processes has a port number,
port number is used for identify processes on the host
port numbers are divided into two types
1.fixed port(ex:25,80)
2.os assigned dynamic port nos(0-65535)
so the port no’s range can be 0-65535

Mac stands for media access control
every computer,router,mobiles..etc haave mac address
it is physical address/hardware address cant changed
mac address used to uniquely identify devices on a lan
represented in hexadecimal
has 48 bits

ISP gives us 4 things

ip address: divided into 2 parts network id,host id nid(network id): starting address of the network all zeros in host id directed broadcast address:put all 1’s in host address,it is the last address in the network

published: false —- default gate way network address broadcast address

Dividing a big network into many smaller networks is called subnetting.

CIDR stands for classless inter domain routing
there are some disdavntages with calssful addressing cidr will solve those issues
in classfull adressing if we want 100 ip adresses we can go for class c which have 256 hosts,if we want 300 ip’s we can go for class b which has more than 300 ips
cidr solve that issue by giving required number of ip addresses in block form
cidr blocks will always contains addresses in the power of 2 like 2^8,2^9…etc
There’s no classes in cidr,so how can we find network id ,host id? cidr notation will tell that,cidr notation will look like this 192.168.1.1/24,here 24 bits used for nid,remaining
bits used for host id.

subnetting in cidr

ex:20.30.40.10/25 we need 2 subnets lets find host bits host bits falls on last octet last 7 bits cause nid 25 bits convert last octet to binary

As we have seen in previous post ip address is of 32 bits
With 32 bits,we will get 2^32 diffrent ip addresses,by using formula 2^n (n is the number of bits)

We can assign private ip addresses only to our devices
to access internet we need public ip
isp provides us a one public ip address to access internet
this process done by tthe NAT

lets see ip address of our devices first

windows users

open command prompt and type ipconfig
you can see IPv4 address and IPv6 in the window.

Linux users

open terminal and type ip a based on ur interface u can see ip address if wifi see under wlp6s0 or if ethernet based connection see under enp7s0 ,u can see ur private ip address beside inet like this inet 192.168.1.2

<!— If two people wants to talk to each other they must follow some rules which will make communication effective ,rules include common language known to both parties,grammer,speed …etc,likewise two computers can talk to each other by help of procols.

Switch:

As we all know computer networking is essential for cybersecurity,here i am writng a small post about computer network.