Can I get a USB console?



  • While learning/tuning my pfSense install, I have locked myself out a few times, and had to hook up an external kb/monitor to pfctl -d to get back in.

    As is the trend these days, my pfSense box ( https://forum.pfsense.org/index.php?topic=114202.0 ) doesn't have a serial port, just USB ports.

    I was just wondering if there was a way to get a USB console? 
    (I know I won't be able to connect to it until after the system has finished booting, but that's a big improvement over not having a console at all.)

    Any help much appreciated.


  • Rebel Alliance Developer Netgate

    No, you can't use USB/Serial adapters as consoles. The operating system doesn't see the serial port until the USB subsystem comes up.

    Our SG/XG firewalls that use ADI hardware have what appears to be a USB console since you hook into it via USB, but internally on the board it's still wired up as a physical serial port to the operating system, which is connected internally to a USB/Serial adapter and presented as USB. So while it is a "USB Console" it's not at all the same as a typical adapter setup. In this setup, the OS sees the physical serial port at all times since it is a hardware serial port not USB, from the perspective of the OS. It's the means used by the client to access the port that differs.



  • @jimp:

    No, you can't use USB/Serial adapters as consoles. The operating system doesn't see the serial port until the USB subsystem comes up.

    Our SG/XG firewalls that use ADI hardware have what appears to be a USB console since you hook into it via USB, but internally on the board it's still wired up as a physical serial port to the operating system, which is connected internally to a USB/Serial adapter and presented as USB. So while it is a "USB Console" it's not at all the same as a typical adapter setup. In this setup, the OS sees the physical serial port at all times since it is a hardware serial port not USB, from the perspective of the OS. It's the means used by the client to access the port that differs.

    Thanks for the reply Jim - I know that a console during boot isn't possible over USB, and I can live with that.

    Is there not a way to get a console AFTER the system is up and running?

    If I bring a USB console up and leave it connected, I can still get in if something happens and I lock out ssh/http(s).


  • Rebel Alliance Developer Netgate

    Not that I've ever seen. The same limitations apply for that role.