Realtek RTL8192CE can't see hAP ax2

RouterOS Wireless Networking
1

I occasionally get old computers to rebuild. One today surprised me - it was unable to see my Wi-Fi running through a hAP ax2. Just not shown at all. Fortunately, I’ve got a hAP ac lite on the bench and it could see that. Appreciate it’s only going to see the 2.4GHz interface. Specific bit of the configuration:

/interface wifi security
add authentication-types=wpa2-psk,wpa3-psk disabled=no name=middle-earth passphrase=****
add authentication-types=wpa2-psk,wpa3-psk disabled=no name=shire passphrase=****
/interface wifi
set [ find default-name=wifi2 ] channel.skip-dfs-channels=10min-cac configuration.country=“United Kingdom” .mode=ap .ssid=“Middle Earth” disabled=no name=private-2g security=middle-earth
set [ find default-name=wifi1 ] channel.band=5ghz-ax .frequency=5500,5660,5260,5580,5180 .skip-dfs-channels=disabled configuration.country=“United Kingdom” .mode=ap .ssid=“Middle Earth 5G” disabled=no name=private-5g security=middle-earth
add configuration.mode=ap .ssid=“The Shire” datapath.vlan-id=10 disabled=no mac-address=4A:A9:8A:64:E9:B9 master-interface=private-2g name=guest-2g security=shire
add configuration.mode=ap .ssid=“The Shire” datapath.vlan-id=10 disabled=no mac-address=4A:A9:8A:64:E9:B8 master-interface=private-5g name=guest-5g security=shire

Going to have a play. Thoughts are it’s an old card (in a PC) that doesn’t support wpa2-psk (!) or the 2G AX mode?

PS. Intrigued that there isn’t a channel.band=2ghz-ax in there. Added it and no difference. I did a factory reset earlier to see if that worked (it didn’t) and the default script had the channel-band in it. Not the first time I’ve come across quirks like that. Guess ROS v7 is rapidly changing.

PPS. Stuck a USB RTL8188ETC that I had lying around - no problem there.

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Later… yes, it’s channel.band=2ghz-ax that’s the “problem”. Change to channel.band=2ghz-g and this old card can see Wi-Fi. So the next question is a) is there a problem with the 2G AX implementation in ROS 7 or b) are some old Wi-Fi network chips just not compatible with 2.4GHz AX?

My ten year old Kindle can’t see 2G AX either.

Doing a bit of Googling and found this “The good news: Wi-Fi 6 routers are completely backward compatible with all older Wi-Fi devices that support earlier versions, including 802.11 ac/n/g/b/a”. Hmm… completely backward compatible suggests it should work…

Although I’m guessing it’s a driver/Realtek issue as there are quite a few posts about problems connecting to AX on different vendors like Netgear:

https://community.netgear.com/t5/Orbi-Pro-WiFi-for-Small-Business/Older-laptop-with-b-g-n-wireless-card-can-t-see-SSID-on-SXR30/td-p/2205374

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I’d attribute this to driver for that wireless card. Some are brain damaged enough to barf on features they don’t recognize. As AX AP sets some bits to capability/feature list, which were “reserved for future use” back in time, it’s up to driver to ignore those. But some drivers program hardware in a way that those are not ignored. Or, even worse, some vendors implemented some proprietary features and indicated availability by hijacking those “reserved for future use” bits … now drivers barf because they see those bits set and mis-interpret their meaning.

TL;DR: when old devices running old drivers have problems with modern standard-conforming hardware, it’s always the problem in those older devices.