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I have a wl12xx wifi adapter that unfortunately does not seem to support creating multiple access points. If I run iw list it outputs this line:

    interface combinations are not supported

If I run hostapd with multiple SSIDs set up if sometimes runs, and sometimes gives me too many files are open, or device or resource busy. In any case I have only ever seen it make one wifi network.

As I understand it, a BSSID is basically the wifi card's MAC address, and the standard way to create multiple APs with hostapd is to create multiple network interfaces, each with their own BSSID (MAC address) and SSID. It's as if you had multiple physical network cards.

This mode appears to be not supported by my hardware but I actually only want one network (BSSID) with multiple SSIDs. Is it possible to do this? Does hostapd support it (there's very little documentation for it)? Does the wifi standard allow it?

To put it in other words, instead of this:

# First network on wlan0.ap1
interface=wlan0.ap1
ssid=my_first_ssid

# Second network. `bss=X` starts a new section, using the network interface X.
# I think that's how it works anyway. Documentation is very unclear and the config
# file format is idiotic.
bss=wlan0.ap2
ssid=my_second_ssid

# Third network.
bss=wlan0.ap3
ssid=my_third_ssid

I want something like this. A single network that broadcasts itself as three SSIDs.

# Single network on wlan0.ap1 with three ssids.
interface=wlan0.ap1
ssid=my_first_ssid, my_second_ssid, my_third_ssid

Or maybe something like this would work?

interface=wlan0.ap1
ssid=my_first_ssid

bss=wlan0.ap1 # Same interface
ssid=my_second_ssid

bss=wlan0.ap1
ssid=my_third_ssid

Or this?

interface=wlan0.ap1
ssid=my_first_ssid
bssid=02:01:03:04:05:06

bss=wlan0.ap2
ssid=my_second_ssid
bssid=02:01:03:04:05:06 # Same BSSID

bss=wlan0.ap3
ssid=my_third_ssid
bssid=02:01:03:04:05:06

Am I going to have to read the source code?

2
  • 1
    Did you ever find an answer to this question? Jan 5, 2019 at 19:58
  • I don't think so, sorry :-/
    – Timmmm
    Jan 6, 2019 at 22:26

1 Answer 1

1

I'm afraid you really need hardware that supports interface combinations. You can't have multiple SSIDs on the same interface with hostapd. I can't tell whether that's right or wrong from a standards point of view.

Here is what it looks like with my wifi card

valid interface combinations:
    * #{ AP, mesh point } <= 8, #{ managed } <= 1,
    total <= 8, #channels <= 1, STA/AP BI must match

and with this hostapd configuration

interface=wlp5s0
ssid=ap1

bss=wlan-ap2
ssid=ap2

bss=wlan-ap3
ssid=ap3

The additional network devices are created when hostapd starts. ip link shows:

10: wlp5s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br0 state UP mode DEFAULT group default qlen 1000
    link/ether xx:xx:xx:xx:xx:40 brd ff:ff:ff:ff:ff:ff permaddr xx:xx:xx:xx:xx:42
11: wlan-ap2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether xx:xx:xx:xx:xx:41 brd ff:ff:ff:ff:ff:ff permaddr xx:xx:xx:xx:xx:42
12: wlan-ap3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether xx:xx:xx:xx:xx:42 brd ff:ff:ff:ff:ff:ff permaddr xx:xx:xx:xx:xx:42

Note that I had to modify wlp5s0's MAC address to allow this to work.

1
  • could u plz kindly share your wireless card model? thanks,
    – Xb74Dkjb
    Sep 27, 2022 at 2:54

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