That's a bad analogy. It wrong because you can see what doors, cupboards and drawers are available for the public. Doors that are in-reach but that shouldn't be used by the public have signs like "restricted access" or "employees only". You can't do that with the internet. You can't see that a port is not available to you until you try it.
If you want to continue using that analogy, then you have to consider that everybody is blind and deaf, and checking to see what's locked is the only way to know if something is available.
> That's a bad analogy. It wrong because you can see what doors, cupboards and drawers are available for the public. Doors that are in-reach but that shouldn't be used by the public have signs like "restricted access" or "employees only". You can't do that with the internet. You can't see that a port is not available to you until you try it.
But you can see what ports/doors are available. TCP doors are defined in the RFC and they are numbered 0-65535. Those are the ones available.
Port scanning still is analogous to trying all these doors and see which one are open.
Just because it is a lot of doors to choose from doesn't make it very different. That's why guests ask a host where the bathroom is.
When you visit a website, it's not very cool for that site to check which of all your TCP ports are open. It's none of their business.
I made this edit to the post you replied to. You probably missed it:
> If you want to continue using that analogy, then you have to consider that everybody is blind and deaf, and checking to see what's locked is the only way to know if something is available.
About this:
> instead of waiting for the guy to tell you which one to go to?
How does that translate to TCP/IP? What is "the guy" representing? The way I see it, there is no guy.
If you want to continue using that analogy, then you have to consider that everybody is blind and deaf, and checking to see what's locked is the only way to know if something is available.