I know that there are similiar questions out there but not worked for me. I've set up a static ip for my wlan0 interface. that works well when I'm also connected via ethernet. but as soon as I disconnect the cable I can't ping to the defined wlan0 ip or ssh. the strange thing is that my router knows that my pi is connected via wifi.
If I boot with only the wifi dongle...it still does not work.
here is my interfaces file:
auto lo iface lo inet loopback auto eth0 iface eth0 inet manual allow-hotplug wlan0 iface wlan0 inet manual wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf iface sky inet static address 192.168.1.41 netmask 255.255.255.0 gateway 192.168.1.1 iface default inet dhcp