Thank you very much, senior bpwl, for your reply which is marked as the solution as it helped me to finally understand what I had to add to the default configuration to make my device doing both getting traffic from another Wifi AP and NATting it both to the Ethernet ports and over its own Wifi AP. I was looking for that solution several times, including this forum, and all my previous attempts failed. It also helped me to understand how to convert the ether1/WAN port to an usual LAN port, which is pretty neat thing on my device because it has just 3 Ethernet ports in all.
And I'm total newbie to RouterOS.
The three essential things for me to understand were:
- virtual WLAN2 needs to be part of the one and only bridge along with all the LAN ports;
- WLAN1 must be in station mode, while WLAN2 in ap-bridge mode;
- DHCP server must be assigned to the bridge.
What annoyed me the most was the fact that many other much simpler and cheaper routers has this feature/mode working out of the box. But meanwhile I couldn't find a solution for RouterOS to make the same setup working. IMHO this mode should be one of the default modes on the Quickset page, because it's very widely demanded, much more often than CPE mode, especially for the devices with two radio bands and for those devices that allow to add additional Wifi modules/adapters.
I have a question not concerning RouterOS but Wifi itself. It's probably a pretty silly question. Why is there that limitation that Wifi adapters can't switch fast enough to support two (or more) access points using different radio channels? Is that just hard (or too expensive) to implement or is that deliberately limited by the standard?
You triggered my "Virtual WLAN" response, because you said "repeater". A one wifi radio device can be a "repeater", accepting a wifi connection from a network, and have clients at the same time by using two functions on the same radio. (hAp ac2 has 2 radio's, one in the 2.4 GHz band and one in the 5 GHz band.) The virtual WLAN is only needed here to be able to have clients connecting on both radio's, while having a connection to the ISP at the same time. It's not ideal. It's sharing that capacity for the 2 functions. But with a single radio hAP (hAp Lite, mAP, ...) it would have been the only way. If you want the full performance and can connect all clients to the other band, don't use that virtual WLAN. (or just disable it)
Creating WLAN and Virtual WLAN is also done, when you hit "Setup Repeater" in Winbox while looking at the master WLAN.
Another reason for having virtual WLAN, is when you have more than one SSID. (Other brands typically give you the ability of using 4 SSID's per radio). A second SSID here, on the same radio, will require a virtual WLAN. (it has it's own settings like mode, SSID and security, but uses the same frequency as the master WLAN). You can have more then 4 SSID's this way. (The practical limit is 20 as you share the capacity, the software limit is 127 per radio)
Your WLAN's are all connected to the bridge. So data flows equally, independent on what WLAN you are connected. Using one band for the uplink and the other band for the clients is no problem. It is called "repeater turbo mode" with some brands, as there is no performance penalty for sharing the radio for 2 functions. It's the preferred setup for performance.
In the hAP ac2 WLAN1 is for band 2.4 GHz, and WLAN2 is for band 5 GHz. They are both master WLAN. One master WLAN is for one radio. Both WLAN can have the same SSID (and security). Clients will roam between the 2 SSID on the clients decision. (normally based on signal strength, and mostly preferring 5 GHz these days).