Hey, folks! I had begun configuring VLANs recently, and I’ve got two managed switches between my firewall and my mini PC. I set up a 10 VLAN on the third octet with a /24 mask, and the idea is that anything on 10 should be able to reach the internet but not VLAN 1, while VLAN 1 should be able to access the internet and VLAN 10 services. I’m not so crazy as to try to start with that configuration though. No ports or anything are exposed yet, so my first test was just going to be full access between networks. I maybe counted my initial configuration as a success too soon, because with the mini PC on the 10 network, I can reach the gateway at 192.168.10.1 but nothing else. I can even access the OPNsense config page at the 10 gateway address. If I ping 192.168.1.1, I get “Network is unreachable”. If I ping www.google.com, I get “Temporary failure in name resolution”, and I also can’t pull up sites like YouTube. And again, this is all with a VLAN rule that I believed to be configured to allow all traffic, as it mimics what’s set up for my default LAN interface. Pinging the mini PC from the 1 VLAN also fails; it just sort of times out with 100% packet loss, so perhaps the default rule is less permissive than I thought, but it does say it allows all.
I’ve been following beginner guides from the Home Network Guy (a name that makes this stuff sound more approachable than how he actually presents it), but even with a video that’s not even 3 years old, pieces of OPNsense have been deprecated and replaced with new components such that I can’t follow along verbatim. For instance, it was an ordeal to get DHCP working now that the one he used has been replaced with Dnsmasque DNS and DHCP, and I can’t even tell you what I changed that eventually got it working, but my first couple of tries did not. In one of those videos I’ve been following, he indicates that the default rule on the LAN interface will allow full access between all networks, but that doesn’t seem to be the case, as the same settings on the other VLAN aren’t allowing them to talk to one another.
Obviously, I don’t intend to leave full access between the networks when it’s time to go live, but this simple smoke test shows that there’s a gap in my understanding if I can’t get what should be the easiest test to work. Does anyone know what I’m missing or what I should do to troubleshoot from here?
I’m a bit late to the party. I was a network admin in another life and believe I can help out. I’ve skimmed existing conversations but not fully poured over them.
That said: I’d print the routing tables for the switches and firewall and review them. Considering firewall rules is sensible but it seems you’ve already done quite a bit of investigation there. It sounds like there is some vlan configuration missing. Like one of the switches doesn’t have the vlan interface defined or named in its vlan database.
Review the routing tables and confirm who owns each vlan and what those networks are aware of. Also toggle your logging options on so you can review them and test with more info than pass/fail.
It very well may be a OPNsense firewall knowledge thing but I’m not convinced. If you’re still working on this tomorrow I’d be happy to help root-cause the problem and fill in the gaps between RTFM and old YouTube videos. :)