9.1 Connecting devices
So far, you have been using network simulators to learn how to connect and configure network devices. Computer simulations are really useful tools for learning about computer networks, but it is also helpful to see the physical devices that these simulated components represent.
Knowing what these devices look like and, for example, where to plug the cables in, should help you associate the computer representations with the real thing.
In this first video, you will see what a server room is like. You will see network devices, such as switches, routers and servers, in action. A server is simply a computer, but as it usually serves a single function, or a limited set of functions. It doesn’t have a user driving it, so it doesn’t need a monitor, keyboard or mouse.
Watch the video now, which is about 2 minutes long.
Activity 1 Think about
1. In the video you saw many switches and routers. What is the difference between a switch and a router?
A switch connects devices in a single network; a router connects networks to other networks.
2. The video also showed lots of flashing lights on the devices. What were these indicating?
The flashing lights indicate that data is being transferred.
3. At the end of the video you saw some servers. What kind of servers were mentioned? Do you know what these different kinds of servers do?
Web servers host websites; file servers store files, telephony servers offer digital phone services.
Now watch the video below, which is about 3 minutes long. It starts by showing a lab environment where two laptop computers are being connected to a switch using Ethernet cables, and the switch is connected to a router.
The video also shows an equivalent network being created in the Packet Tracer network simulator. Later in this session you will have a go at building the same network using PT Anywhere.
Activity 2 Think about
1. Could you make out how many ports the Packet Tracer switch had? How did this compare to the physical switch in the lab? What about the router – did it have many ports?
In Packet Tracer you may have been able to see that there were 24 Fast Ethernet ports on the switch, whereas the switch in the lab had 48. The router (both simulated and physical) had just a few ports (which is typical), but these provide Gigabit Ethernet connections. In fact the router used in the Packet Tracer network is actually a representation of the same model of router (2900 series Cisco router) used in the first video.
2. In the video, which devices were connected to the switch?
The laptops and the router were connected to the switch.
3. What was the router connected to and why?
The router was connected to the switch and also connected to a socket on the wall which provided access to the internet. Routers are needed to connect a network to the internet.
Activity 3 Try it out
As a revision exercise, useto create the same network that you saw in the video. You will need to drag into the main screen the devices that will make up the network, and also the cloud symbol that represents the internet. Just build the network for now making the necessary connections between the devices. You don’t need to configure any devices (unless you want to do this to practise what you have learned earlier in the course).
Hint: when making the connection between the cloud and the router, choose the Cloud’s Ethernet interface.
Here is an image of the finished version of the network.