Switch, Hub and Router

Question

Can someone explain me the difference between those three devices?

In: 1512

Answer 1

Imagine a bunch of garden hoses. You need to get some tap water to a small pool for the summer, some pond water to a decorative pond, and some rainwater to a storage tank.

A hub just connects all the pipes together: everything flows to all the pipes and it’s the end valve’s responsibility to turn off the flow to unintended places, which causes three things: one, you can only pump one thing at a time; two, after you’re done pumping the pond water and want drinking water, now you have to drain the system to prevent mixing waters (in Ethernet, it takes some time between the device ending a connection and another starting one, since they have to detect that no other device is talking at the same time); and three, you may end up sending water to the wrong place, if the end valves malfunction or were tampered with (data could be stolen that way in the past).

A switch is like a device that connects the start hose and the end hose together automatically, as long as you know the hose numbers (you may put an order to, say, pump from pipe #1, the main water system to pipe #5, the pool). Now you can pump however many liquids you want as long as you have enough hoses, if you know through what exit pipe you want it pouring out of. And since there’s only one start and end connection per set of pipes, you don’t need to wait for another to finish.

A router is like a device that lets you connect your bunch of hoses to your neighbor’s bunch of hoses. So now you can send your water to the neighbor’s pool if you want by just saying “the water from our pipe OURS#1 goes to the neighbor’s pool”, and the neighbor’s switch (their local device handling their bunch of pipes) will automatically connect it to their pipe NEIGHBOR#4. A router deals with higher level information than straight pipe numbers, hence why they don’t need to know what pipe the neighbor connected their pool to; the neighbor could change their pool to pipe #12 and it would still send it successfully.