Objectives - Topic 3

Students will be able to:

  • 3.1.1 identify different types of network (VLAN)
  • 3.1.2 outline the importance of standards in the construction of networks.

Protocols

A protocol is an established set of rules that devices wanting to connect and communicate on a network must follow.

Some examples are:

  • http and https for communicating on the Internet
  • smtp for sending/receiving email
  • tcp/ip for transferring files across the Internet

Personal Area Network (PAN)

A PAN is probably the smallest of all networks. Even connecting your smartphone to your earbuds via bluetooth can be considered a PAN.

Easy to set up and allows people to connect their devices at home.

Network Traffic

When the network gets busy with lots of users connected, it can slow down. Perhaps the available bandwidth cannot handle the traffic that all the users are generating.

For this reason, some staff come to the office earlier in the morning when it is not so busy. The network is much quicker then.

Routers

Routers control the flow of traffic between networks.

They inspect the address on a data packet and ensure that the packet is sent on the correct path towards its destination.

Virtual LAN

A network switch allows devices to connect to form a Local Area Network (LAN).

Devices on a network must follow certain in order to communicate.

Often there will be clients and a server on the network. The clients can request files and other resources from the server.

Switches can be quite small with just a few ports such as the one you might have in your at home.

In an office building with many devices connecting to the network, a switch with more than 50 ports could be used.

LAN Issues

In the example above, things are getting pretty busy. There will be a lot of on the network when all of the employees are at work.

If more devices connect and it gets busier, it could become difficult to manage.

There could be a Broadcast Storm!

Also, company has sensitive employee data stored on one of the servers. This data should only be accessed by the accounts department. But because it is on the same switch as, for example, the wifi router, the server is vulnerable to attack from anyone within range of the signal.

Would it be a good idea to cut the network up into smaller networks, making it easier to manage and improving security?

Network segmentation is the process of dividing a network into smaller segments to improve performance, security, and resource management.

Segmentation Strategy 1: Subnetting

One way to make a large network more manageable and improve/limit the accessibility of certain devices is to break the network into smaller networks, connected by a router(s).

Now there are 2 sub networks each with its own switch. The subnetworks are connected by a .

Network traffic on one sub network does not affect the other one, unless a device on one network is communicating with a device on the other one.

This is a neat solution to help manage a network.

However it can be expensive as new switches, routers and cables need to be purchased.

Also, to connect a user to the network via Ethernet cable, the user might have to be in the same physical location as the switch.

This can be awkward in an office building where the same members of a department are on different floors, for example.

Segmentation Strategy 2: Virtual LAN (VLAN)

The ingenious engineers who design network equipment solved the above problem by creating a Virtual LAN.

This is where every device can be connnected to a single switch, and the ports in the switch are programmed to create subnetworks.

Find the sales team's printer. Click its port in the switch to reprogram it to join the admin team's sub network.

It's that easy! You didn't need to lay new cables or move the printer from its current location to join the subnetwork!

A Virtual LAN is considered to be a logical network rather than a physical one like an ordinary LAN.

Exam Questions

Using the information on this page, complete exam questions.

Resource 1

Watch the video for more insight into V-LANs.

Resource 2

Complete the worksheet.

Printables

Glossary

Virtual LAN

sub network

switch

router

client

server

physical network

logical network