Doriano Carta

A friend of mine said to me, “Sorry you have to work late tonight. I have no idea what a core switch is.” It made me chuckle and remember that most people don’t know the terms or jargons we geeks in I.T. use on a daily basis. Even technically savvy users like my friend don’t always understand how a network works. After all, it isn’t their job to know this stuff anyway.

Still, I always like to provide a little basic networking 101 to my network users just so they can get an idea of how it all works. I will give them a quick and dirty tour of the network operations center (sometimes called the Computer Room or Data Center, depending on the ego of the IT Manager). I like to demonstrate what happens every time you power on your laptop or desktop computer and log into my network. I want to show them that it isn’t just voodoo or magic or just dumb luck whenever things work.

Here is a basic diagram that I like to share with my network users that shows a simple overview of the entire process. Keep in mind that this map was designed for the average network user so please stop chuckling you I.T. knuckleheads.
For a larger image click this: networks101

Here’s what goes on every time you power on your laptop or desktop on a network.

1. Laptop/desktop powers on and loads operating system

2. The computer’s network card establishes connection with the network via an ethernet cable plugged into the wall jack or via wireless access point and wifi card.

3. The user enters their login information and it is sent back to the network server for authentication and verification.

4. Note that everything flows thru the network switch which connects all desktops/laptops, printers and servers inside the firewall which protects everything from the Internet and outside world.

5. Once a user is connected to the network, then they can access whatever has been assigned to them. For example, they can send print jobs to the printers they have permission to print to and access files on the file servers.

6. All emails enter the network from the internet after the firewall inspects it and forwards it to the company’s email server(s). The emails are then routed to the mailbox owners after being screened for viruses, spyware and spam. (It’s not an exact science, but most harmful elements are caught in time).

There you have it in a nutshell. The core switch is the hub of any network. It is the traffic cop that controls the flow of bits and bytes that travel across the network continuously. Even untethered items like laptops that use WiFi to connect to the network wirelessly still use an access point that ultimately connects to the switch via a network cable.

I hope this simple explanation and diagram gives a glimpse at the complexity of your local area network and perhaps a little more appreciation for the unsung heroes in your I.T. department (cough cough). Next time you see them, why not give them a hug? OK, scratch that. You don’t want to freak them out or anything, so a simple smile and head knod will suffice.