Oleksij I looked at https://unix.stackexchange.com/questions/122050/ send-traffic-to-self-over-physical-network-on-ubuntu It appearred to too complicated but https://unix.stackexchange.com/questions/122050/ send-traffic-to-self-over-physical-network-on-ubuntu with: # Create a network namespace and move one of interfaces into it: ip netns add test2 ip link set wlan0 netns test2 # Start a shell in the new namespace: ip netns exec test2 bash # Then proceed as if you had two machines. When finished exit the shell and # delete the namespace: ip netns del test2 Certainly looks interesting but after I got a RTNETLINK answers: Invalid argument I lost interest. My heart isn't in it. I'm still working on the firmware. I have started a new tree (tree #3) that consists of a userland firmware uploader and until recently the following firmware: app_start( void ) {} i.e a lable that the code jumps to and nothing else. At this point I have added VendorCommand(), and a debugger via ep0. ( ep0 is a good choice since it is available a boot, no matter what) and over the next few months I am going to move ->all<- the rom code into ram starting with the USB subsystem. Bruce