21.02 on TL-AC1750

To set the scene: I am new to OpenWrt and I have only basic networking knowledge. I chose to upgrade my router to OpenWrt to segregate my network in different VLANs for security purposes. Unfortunately DSA was only recently introduced (limited 'dummy' documentation) and I am struggling with the DSA concepts, especially in combination with my router (I have two TL-AC1750's).

Most of the DSA examples discuss VLANs in relation to LAN1, LAN2 ... network devices. My router seems to deviate in that it only has a eth0 network device. I configured 2 new VLANs in the Devices section (eth0.10 & eth0.20) and bridged them with the default eth0.1. Also in the Switch section I mapped LAN1 to VLAN1 (untagged), LAN2 to VLAN10 (untagged), LAN3 to VLAN20 (untagged) and LAN4 to VLAN10 and VLAN20 (tagged). Finally, I also created 2 additional interfaces for the VLANs, assigned a subnet to them and activated DHCP.

In the end, it does not work. I only have VLAN1 on port 1, the other ports do not work. Maybe I am still missing VLAN filtering on the bridge?

My questions:

  • Why don't I see LAN devices, but instead eth0? How does my router deviate from other routers in common examples?
  • On the bridge, when trying to define Bridge VLAN filtering, I can map the different VLAN IDs to eth0.1, eth0.10 and eth0.20, but does that matrix make any sense? eth0.x is already related to a VLANx, what mapping do I need?
  • Ultimately, I would like to link my 2 TL-AC1750 routers together with one cable (port 4) and have both routers serve VLANs 10 and 20 (next step is to add SSIDs too). Is that even possible with my routers?

Thanks for any insights,

Doesn't really specify any particular device, but it's often used for the Archer c7/ a7 - in which case, ath79 hasn't been migrated to DSA yet and all the old (swconfig based-) documentation still applies (for the most part).

@slh thanks for your quick response. Does that mean it would be best to stick with v19 until my device is supported for DSA?

Btw: you are right I have an Archer A7 and a C7.

No, 21.02.x or the future 22.xy.z are fine, it just means that the older swconfig based documentation still applies. There is no reason at all to use a deprecated release (19.07.x is being disontinued/ EOLed this month).