Zs has two NIC’s (LAN (192.168.0.0/24) & WLAN (192.168.1.0/24)) and one UMTS/HSDPA over USB for internet.
So pppoe is my gateway (IP is dynamic).
All config after installation/implementation is by default.
What is strange is, that ping goes from 192.168.1.0 subnet to 192.168.0.0 one.
Do I have manually disable this “unwanted” feature ?
If by saying “unwanted” you mean that packets from WLAN are forwarded to the LAN, then yes you have to add some deny rules in the FORWARD chain of the firewall. By default it is set to allow all forwarding traffic.