Asklemmy

43899 readers

1210 users here now

A loosely moderated place to ask open-ended questions

Search asklemmy 🔍

If your post meets the following criteria, it's welcome here!

Open-ended question
Not offensive: at this point, we do not have the bandwidth to moderate overtly political discussions. Assume best intent and be excellent to each other.
Not regarding using or support for Lemmy: context, see the list of support communities and tools for finding communities below
Not ad nauseam inducing: please make sure it is a question that would be new to most members
An actual topic of discussion

Looking for support?

Looking for a community?

Lemmyverse: community search
sub.rehab: maps old subreddits to fediverse options, marks official as such
[email protected]: a community for finding communities

~Icon~ ~by~ ~@Double_[email protected]~

founded 5 years ago

MODERATORS

[email protected]

228

Can someone demystify computer Ports for me? Please? Blocking, unblocking, opening, allowing, VPNs and their effect, what ports are and what they do, step by step, when you have to interact with them? (lemmy.dbzer0.com)

submitted 7 months ago by [email protected] to c/[email protected]

61 comments fedilink hide all child comments

It's the one thing when I'm configuring things that makes me wince because I know it will give me the business, and I know it shouldn't, but it does, every time. I have no real idea what I'm doing, what it is, how it works, so of course I'm blindly following instructions like a monkey at a typewriter.

Please guide me into enlightenment.

you are viewing a single comment's thread
view the rest of the comments

[–] [email protected] 37 points 7 months ago (2 children)

A “port” is just a number that gets assigned to network messages to differentiate targets within the same IP address.

One program is “listening on port 1”, which means it has told the operating system “anything labeled port 1, send it to me”.

It’s sort of like saying “attention: Joe” versus “attention: Sue” on an address. Same address, same building, but that “attention” line means to put it on Joe’s desk inside the building.

Except instead of “attention: Joe”, it’s just “attention: 22”. A numerical code that represents a “mailbox” inside the computer.

[–] [email protected] 4 points 7 months ago

To take this further, if the office mailroom is the router, opening a port is like telling them "we just hired Jeff, so accept mail with ATTN Jeff" and closing a port is like "we just fired Sam, burn all mail addressed to Sam".

[–] [email protected] 4 points 7 months ago

That is The Good Answer.

Another, very similar way of thinking about it is that It's effectively like an apartment or office number. A post office typically ignores it, but if told to, they would forward a specific apartment number at a specific address to a new address and apartment number.