Set Up TCP/IP Networks

The Different Types of Intermediary Device

Let’s go back to the diagram of the very first network we saw in the first chapter:

We’ve already looked at end nodes and the different transmission media that connect them. Now let’s delve into the heart of the network and learn about intermediary nodes.

You might have noticed in the diagram above that there are two different devices:

• Switches. These are devices that connect PCs, printers, servers, etc. 

• Routers. Devices that link all of this together.

Let’s take a closer look!

Identify the Features of a Switch

Switches are the first intermediary nodes you’ll come across in a network, as these are connected to the end nodes - computers and printers, for example.

They play the same role as a roundabout in a road network, or more precisely, a railway switch. As well as serving as an intersection between several directions, they can also direct messages the right way. They are fundamental to connecting different devices.

Despite performing the same functions, different switches can have different characteristics, the main differences being:

• The number of ports, ranging from four to 96, enabling connection of an equivalent number of devices.

• The types of port: Switches can have RJ45 ports for standard network cables, optical interface (SFP+) for fiber optic cable, or a combination of both.

• The speed each port allows: This can range from 10Mbps to 100Gbps.

• Features such as the underlying operating system, compatibility, or communication modes.

Source

Switches are a step up from hubs. A hub is a non-intelligent switch, which means that it’s incapable of determining which direction (via which port) it should send a message. It therefore sends the same message to every port, assuming that this way, the message will arrive at its destination.

This poses security problems and leads to needless network congestion, which is why hubs are now very rarely used, and are not suitable for company networks. Switches and hubs are used for local networks, but to communicate with larger and global networks, you’ll need to use a different piece of equipment: a router.

Identify the Features of a Router

Routers are essential for communication between two networks. Think of them as a bridge between two destinations. In fact, another name for them is a gateway. To go back to the road analogy, they act as a checkpoint at the border between two countries.

Routers serve three purposes:

• They connect two networks that may have different configurations.

• They decide which messages are allowed to pass through in both directions -inbound and outbound.

• If necessary, they direct messages, like a switch.

Like with switches, you should choose your router based on the number and types of ports it has, its speed, and any additional features.

Not really—routers are used for connecting networks to each other, not end nodes. And unlike switches, they have very few ports (often only two or three).

Home routers are a special type of router consisting of a switch, a TV decoder, a file server, and some additional features. Their main role is the same as a traditional router—allowing your messages to be delivered between networks, and therefore, providing you with internet access.

Create Two Connected Networks

Now you’ll be able to finish your client’s project: connecting his PC and his employee’s PC to the file server.

But first, take a look at the video below to find out how to add intermediary devices to your network.

Over to You!

Connect Three Devices to Each Other

Using the network model you created last time, make the necessary changes to connect all devices to each other, minimizing the cabling required.

Answers

You can find the answer sheet here to correct your work.

Connect Two Networks

A year later, Tinos driving school contacts you again for another consulting project. Several businesses share the office space the company rents. One of the neighboring companies, Cyclade (a bike safety company) regularly works with Tinos and needs to be able to share large files.

The client therefore wants a network architecture to make this possible.

• Add an external network composed of the two PCs belonging to the company Cyclade.

• Connect the two networks.

Answers

You can find the answer sheet here to correct your work.

Let’s Recap!

• You need to add intermediary devices into your network to connect more than two devices.

• There are two types of intermediary devices: switches and routers.

• Switches are used within a local network to connect the end nodes to each other.

• One switch can connect several dozen devices, like a roundabout leading to many different destinations.

• To connect a local network to another network, you need to add a router. It acts as a bridge between different networks.

Congratulations, you’ve created your network’s physical architecture!   The next step is to configure communication within your network. But first, test your knowledge with a quiz!