Hello Mikey
Thanks for your reply.
The Arduino Wifi delivers IP adresses to smartphone and to tablet.
On the tablet I can see the used Ip adress and I use this IP adress for communication.
The exact error message on the smartphone which send the command : failed to connect to 192.168.240.2
(port 8000) isConnected failed : EHOSTUNREACH (No route to host)
On the tablet and smartphone I can not check subnetmask. It is not displayed.
When I use a wifi router instead of Arduino wifi, everything works fine.
Thanks again.
Mario