Thank you all for this topic!

I changed the urls with the help of sed command, here is it, for the record:

sed -i -e 's/ar71xx/ar71xx_nand/' /etc/opkg/distfeeds.conf
But it didn't helped me about installing kmod-bluetooth:
root@GL-AR300M:~# opkg install kmod-bluetooth bluez-libs bluez-utils kmod-usb-core kmod-usb-uhci kmod-usb2 usbutils Installing kmod-bluetooth (3.18.27-1) to root... Downloading http://www.gl-inet.com/openwrt/ar71xx_nand/2.26/packages/base/kmod-bluetooth_3.18.27-1_ar71xx.ipk. Package bluez-libs (5.30-1) installed in root is up to date. Package bluez-utils (5.30-1) installed in root is up to date. Package kmod-usb-core (3.18.27-1) installed in root is up to date. Package kmod-usb-uhci (3.18.27-1) installed in root is up to date. Package kmod-usb2 (3.18.27-1) installed in root is up to date. Package usbutils (007-1) installed in root is up to date. Collected errors: * satisfy_dependencies_for: Cannot satisfy the following dependencies for kmod-bluetooth: * kernel (= 3.18.27-1-614a690edd3b9a652fa55d68faabbaf9) * * opkg_install_cmd: Cannot install package kmod-bluetooth.
So it misses the kernel with hash 614a690edd3b9a652fa55d68faabbaf9, as only 74422c6556264a9f9977cf38765072a1 is installable:
root@GL-AR300M:~# opkg list kernel kernel - 3.18.27-1-74422c6556264a9f9977cf38765072a1
I didn't tried resetting factory settings.

Should I try the 2.25 version? I have an ar300m NAND dual band model.