Hello folks! I am looking for some guidance or direction on how to make sure my “server” locked down as much as possible. I know there are several websites/guides out there but was hoping I could get someone to recommend some good ones to use that cover all the bases solidly.
There are just so much info out there, wading through looking for a solid guide when you ignorant is hazardous.
Server is running Mint and hosts my Plex/Radarr/Sonarr stack. Using a locally hosted reverse proxy for any outside connections.
This started as a project to learn linux, so things are a bit shaky on linux understanding but getting better. I used GPT assistance to lock it down to the best of my ability, making sure (or I think) that most obvious firewalls rules were setup…ect.
Thanks for your help :)
Your first concern should be your boundary firewall. You should have all ports closed except the ones that you are definitely using for external services. You should know which ports you have open and why, and what traffic, how much and how often you expect to see on those ports (8080 will have regular Internet use traffic, but your reverse proxy port should only have traffic when you’re away from home and actively using it), and you should monitor that traffic at the firewall every so often, and especially when you make changes to your network. Closed ports should be configured to drop packets rather than respond that the port is closed (stealth mode). On a home network, preventing unwanted incoming connections will protect you from the majority of malicious activity. It’s the most effective single thing you can focus on.
The next thing would be to separate untrusted devices onto dedicated VLANs. This would be for IoT devices, gaming consoles, “smart” appliances, anything that connects to the Internet whose software you don’t have control over. They get isolated on a VLAN that only connects to the Internet and doesn’t allow local connections to devices on other VLANs, so the rest of your network doesn’t exist as far as they’re concerned. This should cut down on things like “smart” appliances taking inventory of your home network and reporting it back to the manufacturer’s servers.
If you do these two things, and you’ve got your reverse proxy configured properly so that other people can’t break into it, you should minimize unwanted connections to your network and your server/containers should be fine with default internal firewall policies. The only reason you would need to do more is if you expect a direct/intentional attack by a motivated hacker, but in that case there’s not much you can do unless you’re an expert.
If you want to go further, try implementing the community version of runZero:
https://www.runzero.com/platform/community-edition/
https://help.runzero.com/docs/self-hosting/
https://www.cisa.gov/resources-tools/services/runzero-community-edition
This is a network visibility tool that will discover and identify devices. To get a really complete look, you would run it from inside your network and deal with anything that you don’t think should be accessible, then run it again from outside your network to see what a potential attacker would see.