This question (and answer) relate to an obsolete OS and not relevant to ANY current system.
I have a Raspberry Pi B+ which is connected to my modem/router via a TP-Link TL-WN725N usb adapter. It works fine, however if i turn off the router and than back, the Raspberry doesn't reconnect automatically. I need to plug and unplug the adapter back.
This is the content of /etc/network/interfaces:
interfaces auto lo iface lo inet loopback auto eth0 allow-hotplug eth0 iface eth0 inet dhcp auto wlan0 allow-hotplug wlan0 iface wlan0 inet dhcp wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf auto wlan1 allow-hotplug wlan1 iface wlan1 inet manual wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
I have a static ip reserved by the router