Mavproxy as network to network proxy

Is it possible to use the mavproxy as network proxy server to be able to re-transfer mavlink packets from one subnetwork to other one? (this is necessary due to complicated network structure, where typical port forwarding will not help)
As I understood, mavproxy is able to hold only one IP connection at a time (on --master OR on --out), whereas simultaneous use of two IP addresses (one for master and second for out) is not possible. I’m also unable to use different ports via same network card for the master and out, for example: --master=tcp: --baudrate 57600 --out=udp:
Such commands will operate without errors, will establish master connection, but the --out will not work, e.g. --out=udp: or --out=udpin: or tcpin; not accessible both from local or wan lan cards.
So I suppose that the mavproxy is NOT able to hold TWO IP connections SIMULTANEOUSLY, right? It might hold only one: for master or for out, but not simultaneously, right?

Sorry, that’s not correct, it’s more than capable of holding more than one
IP connection up.

What error are you getting?

There are two NICs in the computer, that should serve as a mavlink proxy by running

  • eth1:; it is connected to the drone’s companion computer, that is running mavproxy
  • eth2:; it is connected to the windows machine (, that is running MP (1.3.56).

The drone’s companion computer runs as follow: --master=/dev/ttyACM0 --baudrate 57600 --out=tcpin: --aircraft MyCopter

The mavproxy on the computer with eth1 and eth2 was started in the manner: --master=tcp: --baudrate 57600 --out=udp: --aircraft MyCopter ; and MP on the windows to connect over UDP - no heart beats…
or --master=tcp: --baudrate 57600 --out=udpin: --aircraft MyCopter ; and MP on the windows to connect over UDPCI to - no heart beats…
or even connecting windows machnine physically to the FIRST subnetwork and --master=tcp: --baudrate 57600 --out=udpin: --aircraft MyCopter ; and the MP UDPCI to

(in all mentioned cases master connection has been successfully created)

all these combinations does NOT provides any errors, simply they return No heart beats (I was trying with tcp instead udp in the --out too, but also no connection).

P.S. eth1 and drones IP addresses are real fixed wan IPs in real life. I replace them in this discussion only.

Yes, I was partially NOT right: mavproxy is able to hold two IP addresses (for the master and out), but these can be accessible only through single NIC (at least in my system), for example: if --master=tcp: then the output streaming should be done via the same nic --out=udp: but the output into the second NIC --out=udp: will not work .
This means that it is impossible to use the mavproxy as a network-to-network proxy (between eth1 and eth2).