Switch, Hub and Router

Question

Can someone explain me the difference between those three devices?

In: 1512

Answer 1

Hub: Mailman goes to the center of a small neighborhood and use a megaphone to yell out the recipients. People yell back to get the mail. When they’re ready to send mail, they yell for the mailman again to send it off. Alternatively, neighbors can yell at each other to pass the mail along to each other too if the mail is just staying within the community.

Switch: The mailman knows everyone’s address, so they will hand the mail directly to each household. Just like the real world. This makes the whole neighborhood much more quiet, and more efficient since nobody is yelling over another.

Router: The mail needs to go somewhere outside the small local neighborhood. The local mailman doesn’t know how to get this mail to the far away neighborhood, so he sends it up to the regional mailman that can forward (and route) mail between neighborhoods.

Neighborhood = subnet (fun fact, “neighbor” is actually the technical term used to describe adjacent subnets! “Neighboring subnet” is a very common term used in the industry)

Mail = data packet(s)

Wait a second, so you’re wondering: How did the mailman in the Hub or Switch get the mail to/from outside their neighborhoods? Well, they have regional mailman (aka router). The switch and hub mailman only works within the local neighborhood, meanwhile the regional mailman’s job is to route mail between neighborhoods. The regional mailman also will never hand the mail directly to each household, they only work with local mailmen*.

*In the real world, often times your devices have both functions built in, this is especially true for consumer products. Basically the mailmen have training on both local and regional tasks, and can do both. You only see separate router/switch/hub these days in more specialized enterprise devices. In consumer products, when you hear “router” it’s almost guaranteed to be a router/switch combo. Hubs are basically never used these days.

Lastly, another related terminology: Bridge.

You can ELI5 bridge quite literally: Think of like a bridge built between two neighborhoods. It connects two, only two, and exactly two neighborhoods together. Why ever use bridge instead of router? 99.999% of the time, you don’t. Bridges are used in very niche and very specific scenarios that could potentially save a tiny bit of money if your needs are limited.