Issues with creating VLANs

Routers
1

Hi everyone! I am very close to losing my mind so I really need some help. Searching on google has proven unproductive. ChatGPT also can’t help that much.

I have a GL-MT6000 (Flint 2) router with the following firmware version: OpenWrt 21.02-SNAPSHOT / LuCI openwrt-21.02 branch git-22.335.71649-0ecaf74

I have moved to a house in which the walls are very thick so I needed to upgrade my WiFi. I decided to go for the TP-Link Omada hardware (a TP-Link OC300 which is the controller and the TP-Link sg2210mp switch) + APs also from TP-Link.

While I was at it, I decided I also wanted VLANs for separation of devices on networks and to avoid congestion and chattering and bufferbloat.

I managed to set everything up on the Omada side of things, no issues. So the SSIDs are created, the VLANs are created, now I just need to pass them from my Flint 2 to the switch via a Trunk port profile.

Now here comes the big issue. I can’t seem, for the life of me, to get the VLANs setup on the Flint 2 side. Therefore, they are never correctly passed to my Omada mesh network so even though the WiFi networks appear when I look for them on my phone, I can’t connect to any of them because I am getting no IP.

I tried everything I could think of, but no matter what I do, the router does not accept the configuration after I click Save & Apply and it just reverts back.

Let me give you a small description of what I did with just 1 VLAN (the IoT VLAN) for the sake of simplicity:

  1. I went to the Advanced setting, into Luci.
  2. I clicked on Network → Interfaces → Devices and I clicked on Configure on the br-lan device. There, I went to Bridge VLAN filtering and I enabled VLAN filtering by checking the box. I then added VLAN with ID 1 with all the lan options on “untagged, primary VLAN” and I also added VLAN with ID 20 with only LAN 2 as “tagged”, the rest are unspecified. LAN 2 is the port that connects to my Omada switch, so that’s why I tagged it.
  3. I clicked Save
  4. I went to Network → Interfaces → Interfaces
  5. I added a new Interface
  6. Named it IoT, Protocol “Static”, Device “Software VLAN br.lan 20”
  7. Clicked on Create
  8. Filled in 192.168.20.1 in Ipv4 and 255.255.255.0 in Ipv4 netmask.
  9. Went to tab “DHCP Server” on the same interface I just created and clicked “Set up DHCP server” and left everything as is.
  10. I clicked on Save

So now, I just proceeded to click on Save & Apply at the bottom.

The router starts thinking and trying to apply the changes and it fails, and reverts everything back.

I even tried to update these things via the CLI by SSHing into the router. I placed a wrong line of code and bricked my router so I just reflashed it with Uboot earlier today. Everything should be as new now and still it doesn’t work.

ChatGPT says that the GUI is completely borked and there is no way to do this properly but I don’t believe that. There has to be a way, I can’t be the only one wanting to create such a simple, clean setup for my home. Surely there are people that have done exactly this or very similar things before.

Please give me a step by step of what I’m supposed to be doing in this scenario because I’m losing my mind. I feel like I am so close to getting my ideal home network up and running and the router just does not want to collaborate.

I also tried looking on this little post from someone else, but this also didn’t seem to work for my situation: Setting up VLAN on GLINet Flint 2 Router | Ryan Pope

Thank you all in advance! Hopefully one of you can help me out here.

2

I have the same problem using the Advanced LUCI GUI on the Flint 2 non OP24 version. So when I’m editing VLANs on a bridge device, I “un-checkmark’ the VLAN Filtering checkbox and it applies the configuration just fine.