[Notorious]

Networking 101
Connectivity Devices


So, we've learned a couple of things on basic networking. This is going to help us with the hardware part of networks which includes everything: from simple NICs to complex switches and routers. It might seem long at first but trust me, it's not the hardest thing we'll encounter.
(Sinisterly won't let me use the word C-A-R-D so if you seen "*controller" well, you can imagine)

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Network Connectivity Devices
Network Connectivity Devices are the ones responsible for physically connecting each one of our network entities. They are components used to share resources and files in an organized manner. There are different types of them, each with a certain objective in mind, but they don't differ much between a home network and a globalized company network.

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NICs
Network Interface *Controllers are the foundation for connecting your computer to a network. They serve as the intermediary between you and the rest of the world. These usually are built right into your motherboard but, sometimes, will be external *controllers that are inserted into one of your expansion slots. This means that they're the actual components that connect a cable into your computer. They take the data from your cable and spit it out into your CPU making sure that it's been translated.
Each NIC has it's own MAC address assigned to it, which is a 48-bit code used to identify the *controller, that looks like this:

Code:

00:0a:95:9d:68:16

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Repeaters
Repeaters are really simple. They are put into action when your cable isn't long enough to get from point A to point B. In fact, with a repeater you can use two different cables to close this gap allowing you to "extend" the reach of the signal. Not only that, but they're able to remove unwanted noise in a signal as to pass it on in a much clearer way.

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Gateways
Gateways are any piece of hardware and/or software that combine to networks that aren't similar. They are very complex since they work on various different layers of the OSI model to translate the data between the two.
A gateway is pretty much a translator for data.

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Bridges and Routers
Bridges and routers have some similarities but we want to know what's different between them to know when we should use them. In substance, bridges can only check the MAC address of incoming data whereas routers can't:

Spoiler:

Bridges
Bridges are network devices that connect two networks with the function of allowing the networks to act as one. They work a little like repeaters, since they are able to check the MAC address of incoming packets and direct them to the right network. They're used primarily for subdividing a large network into two smaller ones for performance reasons. They work on the Data Link layer of networking which I already talked about here.

Routers
Routers work on the Network layer which means they can not only check the MAC address of devices, but can also examine the IP address allowing them to determine where the packet is coming from and going to. It does this by finding the best route possible, but this is also a con: in fact, routers are slower than bridges because they also examine the IP address of the packet and then find a fast way to send the packets, causing packet-forwarding delays.

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Hubs and Switches
Hubs and switches are very similar devices since they act as a cross-road for all devices connected to them via cable. The difference is that switches are faster because of the way in which they handle data transfer, which I briefly explained here:

Spoiler:

Hubs
Hubs are the devices used to connect every single device to each other through a cabled connection. Any packet that is sent will be rebroadcasted to every other port, even though only the recipient with the correct MAC address will actually listen to the packet and receive it. Pretty much, the computer that is connected to a port on the hub will receive the packet and determine whether or not it was intended for itself, if not it just doesn't accept the packet.

Switches
Switches on the other hand are much smarter than hubs. They read the MAC address of the packet beforehand and then deliver it to the correct port. This way data doesn't get sent everywhere but only to the correct person.

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If you still feel like you didn't grasp the concept, I'll explain it in an easier way:
Hubs - I live in a 4-house neighborhood. My aunt sent me a letter and UPS, efficient as they are, make 4 copies of the letter and place them in every mailbox they see. My neighbors, seeing that the letter was for me, decide to throw their copy out while I keep it since I saw it was for me.
Switches - I live in the same neighborhood but UPS, after having read about hubs and switches, decide to check who the letter is for and give it only to me.

There are some types of devices that are much more used than others nowadays whereas there are others that you very rarely find in normal work offices/companies. In any case, knowing the function of every single one is a good thing to keep in your back pocket for future use.

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Found it interesting but have some questions? Ask me anything and I'll respond as quickly as possible if I feel like it.
Discussion is the basis of anything serious.