A PCI or internal (built into the CPU system on chip) Atheros or MediaTek will fully support multi-SSID. Hardware connected by USB may not, especially if it is Realtek.
If you have the hardware in place and running under OpenWrt (or other Linux) use the iw list command to show the capabilities of the hardware and driver. The "interface combinations" section shows how many APs can be run simultaneously.
MIMO is a different concept. Think of it as a form of modulation. When a radio is MIMO capable, it will try to use it on all links to any device on any SSID.
On either radio, the number of APs and / or mesh points may be up to 8.
Managed is also known as a STA or a client. The 5 GHz can only run one such interface. It is very unusual to have a use case that needs to run more than one STA interface on a radio.
Since the internal radio on my router is acting up; I am trying to use a USB stick.
First I tried a TPlink with car9170 module: two SSIDs worked but the hw was flaky (and I knew that already, so I discarded it).
Now I am trying this one:
050d:705a Belkin Components F5D7050 Wireless G Adapter v3000 [Ralink RT2571W]
When I configure it for 2 SSIDs on 2 VLANs, the wifi interfaces will show only outgoing packets and nothing received. Is this what happens when the hw does not support multiple SSIDs?
valid interface combinations:
* #{ managed, AP, mesh point } <= 4,
total <= 4, #channels <= 1
[ 36.176684] ieee80211 phy0: rt2x00lib_request_firmware: Info - Loading firmware file 'rt73.bin'
[ 36.331162] ieee80211 phy0: rt2x00lib_request_firmware: Info - Firmware detected - version: 1.7
[ 36.464341] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 36.498715] br-lan: port 2(wlan0) entered blocking state
[ 36.504154] br-lan: port 2(wlan0) entered disabled state
[ 36.510037] device wlan0 entered promiscuous mode
[ 38.872422] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[ 38.879223] br-lan: port 2(wlan0) entered blocking state
[ 38.884660] br-lan: port 2(wlan0) entered listening state
[ 38.899308] br-guest: port 2(wlan0-1) entered blocking state
[ 38.905381] br-guest: port 2(wlan0-1) entered disabled state
[ 38.911508] device wlan0-1 entered promiscuous mode
[ 38.999973] IPv6: ADDRCONF(NETDEV_UP): wlan0-1: link is not ready
[ 39.006488] br-guest: port 2(wlan0-1) entered blocking state
[ 39.012270] br-guest: port 2(wlan0-1) entered listening state
[ 39.906330] br-guest: port 2(wlan0-1) entered disabled state
[ 40.484659] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0-1: link becomes ready
[ 40.491633] br-guest: port 2(wlan0-1) entered blocking state
[ 40.497452] br-guest: port 2(wlan0-1) entered listening state
[ 40.945161] br-lan: port 2(wlan0) entered learning state
[ 42.545134] br-guest: port 2(wlan0-1) entered learning state
[ 43.025083] br-lan: port 2(wlan0) entered forwarding state
[ 43.030697] br-lan: topology change detected, propagating
[ 44.625144] br-guest: port 2(wlan0-1) entered forwarding state
[ 44.631112] br-guest: topology change detected, propagating
Same in logread, it looks like with the tplink I tried earlier. Only clue something isn't right, beside not having working wifi, is that the two interfaces never receive anything.
Thanks for the feedback. Unless you have a burning desire to get to the bottom of this issue, I'm ok with disabling the guest ssid and leaving it like that, since I just ordered a Fritzbox 4040 to replace it.
rt2571 is an ancient 802.11g USB card, which never really got 100% reliable - in STA mode, not even talking about AP mode…
(rt2571 != rt73, while rt73 is has better support than rt2571, it's not all glory either, still 802.11g, still USB with serious firmware limitations basically making AP mode impossible in the first place (no support for powersaving clients)). These devices were never made or tested for AP mode support, and that shows - primarily in the given firmware support (bugs, missing features, etc.), but also the driver side - that's before even looking at thermal issues arising from 24/7 continuous operations and the antenna designs.