Thanks. I did it ... and the list of dhcp clients got empty.
I tested with three mobile devices that the wifi connection still works and that I still can open die MoodleBox website without any entry in the list. The list remains empty until a current device renews its lease or until a new device connects to MoodleBox wifi.
For the next test I connected a few Raspberry Pi computers via wifi pinging throw the MoodleBox to my home router. It was no problem for the connection when I deleted the dhcp leases completely. I found that the dhcp client list will be reduced to a minimum when I change the ip address without changing any other wifi setting.
What do you think about a shorter lease time? Currently the MoodleBox uses leases of 4 hours as you set in the configuration
dhcp-range=wifi,10.10.10.10,10.10.10.254,255.255.255.0,4h # Assign IP addresses with 4h lease, subnet name 'wifi'
dhcp-option=wifi,6,10.10.10.1 # Set DNS server for subnet wifi
When a teacher uses the MoodleBox in a classroom from 8:00 to 9:00 then he will get a lot of entries in the dhcp list. When he changes into the next classroom from 9:00 to 10:00 the dhcp list remains full. He must change the wifi ssid and the password for the new class. In this case all devices from the first class will be disconnected. He can use his smartphone for the setting and he must reconnect himself with the new data.
What happens when the MoodleBox is uses as a communication tool in a developing country? When 20 or 25 devices are connected to the Moodlebox then no more devices can connect. And when the persons are leaving the area then it will need 4 hours after they connected until a new device will be allowed to connect.
Would the MoodleBox work for short communication and for the usage in school when the lease time is 20 minutes only?