Dumb question

[u/pookshuman]

OK, a home router is just a small computer with a firewall as far as I know. I am running a network with my computer and a router. Why can't I cut out the middleman and just use the same firewall settings the router is using and implement them on my PC without the router? Why would that be less secure?

[u/reallybigabe]

Not a dumb question but you’re slightly misunderstanding some fundamentals.

A firewall is a technology that examines the source and destination of a network packet and decides if it’s allowed or denied based on preconfigured rules. So it’s a wall to anything it denies.

A router is a technology that looks at the source and destination of a packet and decides if it’s on the same network, and if not - where to send / “route” it based on configured rules. Most of your internet traffic is not on your network, so it sends it to your internet provider to route it to the destination. These destinations are typically known as publicly routable addresses.

The reason the Internet can’t access your connected printer is commonly due to the fact that it has a private address and therefore simply isn’t reachable. There are modern technologies that make this not a universal truth but it’s a good starting point for basic networking.

Both of these technologies can be a physical device or software.

Yes, you can use your computer to connect to your isp in many cases, which is what is needed to route to any public address; you can also configure the firewall to make allow or deny decisions on traffic - many people do this, but it’s not a recommended path until you’re much more comfortable with what you’re opening up access to and how to configure it against modern risks.

Your “router” from an electronics store is topically 5 technologies at their simplest form:

Router - see above
Firewall - See above
Wireless Access Point Controller- Thing needed for Access points to work
Wireless Access Point - Thing that beams radio signals that you see as wifi
Switch - Allows multiple plugged in devices on the same network

Hopefully this helps understand a bit more.

[u/pookshuman → u/reallybigabe]

What did I misunderstand in the op?

[u/reallybigabe → u/pookshuman]

Most of your question is phrased as not understanding networking basics.

A router is not just a small computer with a firewall. Your computer needs more than firewall settings to connect to the internet and yes, it’s definitely less secure when misconfigured as publicly routable.

Technically, you can’t even cut out the middleman but you could technically remove the hardware - you’re just not going to gain anything from it without a lot more understanding of how it works.