iface lo inet loopback
iface eth0 inet dhcp

allow-hotplug wlan0
#iface wlan0 inet manual
#wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
#iface default inet dhcp

iface wlan0 inet static
    address 192.168.42.1
    netmask 255.255.255.0