Basic Networking

 What is Networking?

 Networking is the process of connecting two or more than two devices and share resources or       provide services to each other are called Networking.

Ex- PC1 and PC2 are connected to each other and sending resources.

What is Network?

 A Network is collection of Network devices such as computer, Router, Switches, Servers, or Other devices to share resources.

Ex- Network

• The Primary function of Network is to provide Connectivity between devices.

Network Usage

• Information Sharing: With the help of the network we can share information to each other.
• File sharing: To share the file like image, video, audio, picture, documents we need network.
• Resources Sharing: We can use a centralised machine/device to share the resouces. Like in office we can use a printer to the network that is used by multiple users.

Requirement of  Network

• NIC (Network Interface Card) or LAN card
• Medium
• Networking Devices (Router,switch, Hub, bridge, Gateway etc)
• Protocols (RIP, EIGRP, OSPF, ISIS, BGP )
• Logical Address(IPV4 or IPV6) 

What is Internet?

Nowadays internet covering the wide geographical area. Internet connecting the whole world.

If we want to define internet in one sentence then we can say: Internet is Network of Networks.

Father of Internet: Vint Cerf and Bob Kahn.

Network Hardware or Devices:

To construct a network, there are a few devices that we really want. Allow me to give you an outline with a portion of the essential equipment that is utilized.

Network Devices

1. Host Devices:

 Host devices are the devices that are used by the end user.

 ex- Desktop, Laptop, Smartphone, Tablets etc.

2. NIC (Network interface card): 

A network interface card is a computer hardware component that connect to a networking device to other.

Network Interface Card

NIC also known as LAN card or Ethernet card or physical network interface.

NIC is available in different speed:

  a. Ethernet (10mbps)

  b. Fast Ethernet (100mbps)

  c. Gigabit Ethernet (1000mbps)

Ethernet card has 48 bits address. We will call it as mac address (Media access controller). meadia access controller address also known as physical address or Hardware address. 

ex-00:A0:CC:13:AF:4A

OUI- Organization Unique identfier

3. Transmission media: 

The purpose of the media is to transport bits from one machine to another machine. 

There are basically two  types of transmission media 

   a. Guided 

   b. Unguided

a. Guided media: 

Guided Media. It is known as the physical medium through which the signals are transmitted. It is also called Bounded media.Guided media has a fixed path.

ex-copper wire, FOC (Fiber optics cable)

b. Unguided media:

Unguided media define as transmitted data travel through free space in form of electromagnetic signals.

ex- Radio signals

Some cable categories and DTR(Data Transfer Rate)

RJ- Registered Jack

HUB:

HUB is a networking device which is used to connect multiple devices in the network. 

• This is a layer 1 device.
• HUB works on physical layer of OSI model.
• HUB always broadcast the signals and works on Half duplex mode and shared the bandwidth.

Switch:

Switch is a network device that is used to connect multiple pc's/ severs in the network.

• This is layer 2 device.
• Operates on data layer of OSI model.
• Keeps unicast, multicast and works in full duplex mode.
• Switch maintains MAC-address table.

There are two types of switch:

a. Manageable: In manageable switch we can do configuration and has a console port. We can assign the ip address, create vlan, delete vlan etc. we can modify the configuration.

b. Unmanageable: In unmanageable switch we can not do any changes. They do not have console port.

Bridge: Bridge is networking device that connects different topology and works on data link layer of OSI model.

Router: Router is used to connect different network and IPs subnetworks. It operates on network layer of OSI model. Router is layer 3 device.

There are generally two types of router:

a. Fixed Router: Non upgradable, can not add and remove Ethernet or serial interfaces.

b. Modular Router: Upgradable can add and remove interfaces as requirement (NIC card).

Router are used to figure out what path to use to get a certain destination. By exchanging information about networks between different routers, we are able to calculate a path to get the each destination.

Firewall: Firewall is network security device. This may be software based or hardware based. Firewall controls incoming or outgoing traffic based on a set of rules.

Firewalls are inspect network traffic and drop malicious traffic as the set if the rule. We also use them

to encrypt network traffic. Remote workers can access applications on the

company network in a secure way.

Server: Servers are similar to computers but have a different role in the network. For example,

when you check your e-mail your client is connecting to an e-mail server to fetch your email.

We can understand this with the help of email server might be used by thousands of users so it has to be available

24/7.