Re: Twaddle......Some Analysis.....
"(2) One firewall (with rules set my me)"
OK, but...
1. If you want to be *confident* of your internet security, one solitary firewall is never enough, because if it's porous, you'll never know. So from an architecture perspective, a "minimum viable product" is: two different hardware manufacturers and 2 different software stacks. Configure one as your externally-facing firewall, connected to your router/fibre modem... and configure the second as your inner perimeter. If you have *anything* hosted "between" them, then obviously you have only deployed a stripped-down instance of say nGinx, running in reverse-proxy mode? Right?
2. Whose hardware are you using to host your firewall? CWWK? Or one of their derivative / badged clones? If so... are you 100% confident that your Chinese-made appliance is fully secure? If there were an unauthorized access granted via your internet-facing device, how confident are you that you would detect it? Obviously you're not using anything that's US-made, right?
3. How confident are you that you know who made the NIC or NICs [if it's a multi-port card] you are using for your external connection? How confident are you that the NIC *really is* from the manufacturer you see stamped on the physical socket on the back of your machine... as opposed to a functional clone with the brand name put there as misdirection?
4. Whose software are you using to run on your firewall? pfSense? opnSense? ipFire? Something else? Did you compile from source? How confident are you that the code contains no errors... Linking back to my first point... if you want to be *confident* of your firewall setup, you would have 2 different hardware manufacturers and 2 different software products running your firewalls. And when I say, "2 different software products", I don't mean e.g. pfSense and OPNsense, given that OPNsense is a fork of pfSense - which means that if pfSense contains a vulnerability, there is a serious, non-zero chance it also exists in OPNsense...
5. How do you route and trigger your network alerting? You don't mention a honeypot, so it's possible that you're not hosting publicly-facing content, but what about all the other network activity? Do you route all your logs to a central host using e.g. rsyslog? Have something actually monitoring the logs for anonymous events? Sending out alerts to your mobile?
OK... the chances are that you don't have all the above, perhaps because you don't need it. But if your answer is that the "firewall" you have is a packet filter built in to your home router, then, very respectfully, you have the illusion of security and nothing more...
(3) One network connection to the outside world
1. A single network connection is absolutely fine as long as you don't have anything with reliance on a working connection. If the most critical thing about your connection is that your family will kick off if NetFlix is lost, then a single network connection is probably OK. But if you're trying to do anything serious and you don't have any form of backup?
2. You mention the "outside world" like it's everything on the other side of your firewall. Which might be fine. But... do you have any wireless networking? Bluetooth? Do you have devices that have wide area network connections over say 5G and are also configured to your wireless network? Say the sort of smartphone that can be compromised with a single SMS message?
3. If you do run an internal-only wireless network, have you activated MAC Address filtering on it, and configured your mobile devices to use static MAC addresses on that "known, trusted" network?
4. Do you monitor your outbound network traffic for any evidence of compromised hosts?
5. What's your resiliency if your single firewall develops a fault?
It may well be that few [if any] of the questions I ask here are applicable to your network environment - in which case, good for you.
I ask them not to suggest that you have or are doing anything that may be insecure, but to point out that you can only decide "how much security is 'just enough' " when you have a clear picture in your mind of the assets you are protecting - along with their value ... and the threats you want to mitigate - along with their probability and impact.
I am always ready [and would in fact be *delighted*] to come across someone who has a security setup commensurate with their asset values, threat profile and risk appetite... but after many years of professional experience, I have yet to see that setup.
And I'm not talking about "Fort Knox" levels of security, I'm talking about someone who has done a thorough threat analysis, designed and implemented commensurate controls, then actively monitors their control performance and environment to ensure that they are not vulnerable to drift. I'm talking about someone who knows what their risk appetite is, knows how much risk they are taking - and can demonstrate that the former exceeds the latter ... or that they are actively correcting the imbalance.
I make these points only because in my experience having the illusion of security is worse than having no security. At least if you have "no security" you should be aware of the fact. If all you have is an illusion, you're just asking for trouble.