Hey y’all, I have a small network with opnsense firewall, a unify ap, some client in different subnets, vpn, DNS and some servers.
As I am completely self thought, I got everything to run reading the docs and forums, but I have no idea how to test if what I build is safe and stable.
Are there good up to date tools, or checklists one could follow to audit the different parts of the network (most important the opnsense config)?
What do you check if looking for security issues?
The network mostly relies on client separation through different subnets on different vlans, but I fear I dont understand how for example the vpn and the nas work together in detail to be sure there is no security implication I oversee.
Also: how do you handle client authentication for devices on the same subnet? I know IP/mac-adress ARP entries are easily spoofed and therefore not secure, but I haven’t seen how to do it correctly
Perhaps the easiest, and still at least decent, approach is to just run nmap (or any other port scanner) against your own subnets/IP addresses. That way you’ll at least find out if the firewall allows something trough which it shouldn’t, Also you can run tcpdump/wireshark on destination host to see if it receives packets it shouldn’t.
For client authentication, if ARP filtering is not enough, you could set up 802.1x, but that’s likely a massive overkill (and overhead) for home network. I personally don’t authenticate clients separately. Just WPA2 on wifi and firewall rules to allow/deny traffic between subnets. Sure, it’s pretty easy to bypass, but in practise you’d need to be inside the house to access some parts of the network. But my threat model is mostly about a handful of IOT things which I don’t trust with full network access, not about someone unauthorized getting access to my home network.