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What would be a good analogy for IP addresses and ports?

up vote 14 down vote favorite

What would be a good way to describe ports? I learned about it using this analogy, but it seems pretty inadequate to me:

IP addresses are like street addresses of apartment buildings, and ports are like the apartments therein.

IP addresses are not segmented as a street address is, and second, apartments don't seem at all analogous to ports in terms of behavior.

2 Answers

up vote 4 down vote accept

You can consider an IP number to be analogous to a business's telephone number (reaching the main switchboard), and the port number to be the telephone extension number for one person.

This probably works better when there is no direct-dial to a specific person, and the main number is handled by an automated system.

up vote 3 down vote

As a former student I'd like to confess that for me these attempted analogies about the ports just made a simple thing sound mysterious and in retrospect had absolutely zero insight whatsoever.

What about saying instead that TCP/IP is just a program running on your computer like everything else and ports are just an integer in its configuration. That'd be a start.


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What would be a good analogy for IP addresses and ports?

up vote 14 down vote

What would be a good way to describe ports? I learned about it using this analogy, but it seems pretty inadequate to me:

IP addresses are like street addresses of apartment buildings, and ports are like the apartments therein.

IP addresses are not segmented as a street address is, and second, apartments don't seem at all analogous to ports in terms of behavior.


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up vote 9 down vote

You can consider an IP number to be analogous to a business's telephone number (reaching the main switchboard), and the port number to be the telephone extension number for one person.

This probably works better when there is no direct-dial to a specific person, and the main number is handled by an automated system.

edit

That's a nice point. Welcome to [cseducators.se] - I hope we hear more from you in the future! - Ben I. Jul 2 '17 at 13:32

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