Network: Two or more devices are connected with each other by communication medium, it is called Network.

Networking: The method of data commutation or transferred one host to another host is called networking.

Internet : Multiple networks are connected. Network of networks.

Host : PC, Laptop, server, mobile, printer.

Networking devices for networking are below:

1> Hub: Connect multiple hosts to data communication. It has less number of ports, one broadcast domain and one collision domain.

2> Switch: Connect multiple hosts to data communication. It has more number of ports, one broadcast domain and collision domains are depend on number of ports.

3> Router: Two or more different network are connected.

4> Firewall : Permit/Deny data traffic to protect the organization network.

Topology : Bus, Ring, Star, Tree, Mesh, Hybrid.

Bit: Represents 1 or 0.

Byte : all together 8 bits are called byte.

IP Version4: Represented by bit or decimal format. 4 octet is there and Every octet represents 8 bits.

Exp: 192.168.21.13/24

Subnet Mask: Has two part 1) Network ID : All bits are on. 2) Host ID: All bits are off.

Exp: 255.255.255.0 -> 11111111.11111111.11111111.00000000

IP address classes:

Class A > 1.0.0.0 - 128.255.255.255 [1st octet is network ID]

Class B > 129.0.0.0 - 191.255.255.255 [ two octets are network ID]

Class C > 192.0.0.0 - 223.255.255.255 [three octets are network ID]

Class D > 224.0.0.0 - 239.255.255.255 (For multicast)

Class E > 240.0.0.0 - 254.255.255.255 (For research)

Public IP : Not free, need to purchase IANA or ISP, Unique in world wise.

Private IP : Free, Unique in Local area network, not routable in public network.

For host we can use class A,B,C.

Private IP address range:

Class A > 10.0.0.0 -10.255.255.255

Class B > 172.168.0.0 -172.168.255.255

Class C > 192.168.0.0 - 192.168.255.255

Subnetting: Divided a large network into smaller networks to reduce wastage of IP address.

Exp: 192.168.23.1/26

11111111.11111111.11111111.11000000

Subnetted networks under one single network : 2 to the power 2: 4

host in block : 64 - 2= 62