My goal is to find a readily available USB WiFI adapter that has drivers readily available for use with OpenWrt 24.10.X. Is there a list available anywhere? Does or can 24.10.X support RealTek chipsets? Which USB WiFi adapters with MediaTek, Atheros, and/or RealTek chipsets are supported? Are there any chipsets that are absolutely unsupported?
Must haves
Available for sale in the US via known retailers and not an end of life product
Supports simultaneously using multiple SSIDs in AP mode
Nice to have
Can operate in both AP and station mode simultaneously
Simultaneously supports 2.4 & 5 GHz, or at least supports 2.4 or 5 GHz
Notes: I have spent way too much time trying to figure out which USB wifi adapters are supported, but haven’t been able to find much in the way that is definitive. It seems that MediaTek and Atheros chipsets are generally supported while information on RealTek mostly says to stay away while some info says drivers are available and work with OpenWrt. When it comes to vendor website, it is a mixed bag trying to determine what chipset an adapter uses. The openwrt table of hardware is difficult to decipher when it comes to usb Wi-Fi adapters. Ultimately, when I think I have found the answer, I find contradicting information that leads to more questions than answers.
There has been plenty prior discussion about using USB WLAN cards, use the forum search about it. tl;dr, don't do it, every ~15-30 buck mt7621a+mt79125DBDC (or better) plastic router supported by OpenWrt will run circles around any USB card - and actually works reliably.
Totally get the prior discussion point and also would like to convey what my experience has been like sorting through the information on this forum and elsewhere which is that it is easy to conclude that most adapters are both mediatek and Realtek which is not the case and ultimately makes most of the available info unreliable.
Nonetheless, it seems like this forum is not really meant for what I thought it was and will likely not post anything else in the future.
This is the deal breaker: none of the USB WiFi cards that I have support this, and none support dual-band operation.
On the other hand, multiple mini-PCIe cards with this functionality are available. A card that satisfies all your requirements except "USB", and has multiple happy OpenWrt users on Reddit, is this one:
@patrakov thank you for the suggestion!! What hardware platform do you have the Wi-Fi pci modules in?
I tried the Asus USB-AC53 Nano earlier today, but that uses Realtek which didn’t work and seems like Realtek generally doesn’t work in the OpenWrt ecosystem.
Next up is the ALFA AWUS036ACM 802.11ac Dual Band 2.4/5 GHz WiFi USB Adapter which sounds promising since it has the MediaTek chipset so should let me at least create another AP or a station. Hopefully I will be able to report some positive news soon.
I have no x86_64 platform myself. The recommendation is based solely on Reddit users trying it and reporting success.
In the past, I did boot my Lenovo tablet into OpenWrt for evaluation purposes with various Alfa USB cards, but I have not tested the AsiaRF adapter myself, and I don't actually have it.
Realtek modules generally don't work with OpenWrt, because they have poor upstream Linux support. Mediatek story is much better.
ALFA AWUS036ACM is something that I also have. However, it has an annoying limitation of being able to support only one SSID at a time. I.e., it is unsuitable for your purposes.
You can work around this by using multiple adapters, but a WiFi card that tops at 400-500 Mbps under perfect conditions is not something that should be recommended today.