Wirebook › Glossary › Port forwarding
What is port forwarding?
In one sentence: A permanent rule on a router that sends anything arriving on one port number to one device at home, even if nobody inside asked for it.
A little more
Normally a home router only passes an answer back to a device that asked a question first. That keeps strangers out, but it also stops a friend's game from joining one you host. A port forwarding rule fixes that for one door: anything arriving for, say, port 25565 always goes to the games console.
The rule lets anyone knock on that door, not just your friend, so open only the ports you need, point them at one device that stays updated, and remove the rule when you're done. If your internet provider uses carrier-grade NAT, a rule on your own router isn't enough, because the provider's router has no rule for you.
See it in action
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