You need to load the tun module tun.o to have a virtual tunnel interface.

To accomplish this, you need the appropriate modules tarball for your LEAF Bering-uClibc. It's usually available for download in our FRS, older versions are available in our cvs repository.

Unpack the modules tarball and copy 2.4.26/kernel/drivers/net/tun.o to /lib/modules on your router.

Add "tun" to your /etc/modules.

Save modules.lrp