COMPUTER NETWORKSLAN network and communication through

networking devices

Important Points Before We Start1. Computer Networks2. Client3. Server4. Peer to Peer5. Packets

Definition:A computer network or data network is a telecommunications network that allows computers to exchange data. In computer networks, networked computing devices pass data to each other along data connections.

Advantages Of Network

• Centralized Administration• File Sharing• Hardware Sharing• Application Sharing• User Communication• Network Gaming

Disadvantages Of Network

• Security Concerns• Virus and Malware• Lack of Robustness• Network Failure• Lack of independence• Needs an efficient handler

Ethernet

• Ethernet is a family of computer networking technologies for local area (LAN) and larger networks.

• Systems communicating over Ethernet divide a stream of data into shorter pieces called frames.

• Each frame contains source and destination addresses and error-checking data so that damaged data can be detected and re-transmitted.

Types of Network

Distance Systems located

1m Square meter

10m Room

100m Building

1km Campus

10km City

100km Country

1000km Continent

10,000km Planet

Personal Area Network

Local Area Network

Metropolitan Area Network

Wide Area Network

Internet

NETWORKING DEVICES

LAN Cable (RJ45 connector)

Hub• A hub is a device for connecting multiple

Ethernet devices together and making them act as a single network segment.

Switch

• A network switch is a computer networking device that is used to connect devices together on a computer network, by using a form of packet switching to forward data to the destination device.

Router

• A router is a networking device, commonly specialized hardware, that forwards data packets between computer networks. This creates an overlay internetwork, as a router is connected to two or more data lines from different networks.

• 2 LAN• 2 WAN• 1 LAN & 1 WAN

Difference between Hub, Switch and Router

• Hub distributes bandwidth where as switch provide same bandwidth.

• Routers job is to route packets to other networks until that packet ultimately reaches its destination.

• A packet along with data also contains destination address.

• A hub distributes a message to all systems on the network, whereas a switch sends it to only those devices which need it.

• Collisions are common in case of hub.

NETWORKING TERMINOLOGIES

IP(v4) address

• IP stands for internet protocol.

• It is a series of numbers assigned to any computer on IP based network.

• Two computer on the same network cannot share the same IP address.

• Public IP should be specifically unique.

• It uses a dotted decimal notation to divide the 32-bit IP in four 8bit fields, which can hold numbers from 0-255 known where each group is known as octet.

Example: 128.11.3.31

IP Addressing

IP(v4) address

• The first set of numbers are useful for HIS troubleshooting.

• ISP or router provides the IP address. Also your own system can provide you an IP address.

• A device with correct IP address usually gives a sign that it is physically communicating with the attached modem or router.

• IP address are classified on the basis of under which class they come in.

Subnet mask

• A subnet mask is a screen of numbers used for routing traffic within a subnet.

• Once a packet has arrived at an organization's gateway or connection point with its unique network number, it can be routed to its destination within the organization's internal gateways using the subnet number.

Default Gateway

• It is a router on a IP network that serves as a access point to another network.

• In case of home network, if your ISP provides you with router then that router acts as a gateway.

• If you are using a dial up connection without a router then, ISP’s router acts as a default network.

Media Access Control

• Media access control is a communications protocol that is used to distinguish specific devices.

• Each device has a unique MAC address.

• MAC allows each device to be recognized uniquely by the server.

Common Network Commands

• Ipconfig• Ipconfig /all• Ping <IP/url address>• Tracert <ip/url address>• Nslookup <url address>

LAN CONNECTION

Step 1: Connecting hardware components

Step 2: Turning on Network sharing

Step 3: Turning on Network sharing

Step 4: Starting with file sharing

Step 5: Accessing shared files and directories in Windows 7

Double Click on network

Step 6: Selecting the system

Thank You