pkg_pre_save() 
{
	[ -f /mod/etc/conf/radvd.cfg ] && . /mod/etc/conf/radvd.cfg

	old_address=$RADVD_ADDRESS
	old_interface=$RADVD_INTERFACE
	new_address=$(echo "$settings" | sed -ne "/RADVD_ADDRESS/s/RADVD_ADDRESS='\(.*\)'/\1/p")
	new_interface=$(echo "$settings" | sed -ne "/RADVD_INTERFACE/s/RADVD_INTERFACE='\(.*\)'/\1/p")

	if [ "$old_address" != "$new_address" -o "$old_interface" != "$new_interface" ]; then
		/mod/etc/init.d/rc.radvd remove
	fi
}