hostapd_cli all_sta for eight emulated ap+hostapd in one machine

[Aniss Maghsoudlou]

I have emulated 8 access points namely ap1, ap2, ... , ap8 in my
ubuntu 15.10 machine, each of them running hostapd with
ap1-wlan0.conf, ap2-wlan0.conf, ... , ap3-wlan0.conf respectively.

Whose connected stations does "hostapd_cli all_sta" show?
How should I see any of these access points clients?

p.s. Same question for all the hostapd_cli commands.

Regards,
Aniss Maghsoudlou, M.Sc. Student,
Computer Networks, Wireless Networks Laboratory, Room 808,
Computer Engineering Department, Sharif University of Technology, Tehran, Iran.