Pfsync via serial interface?

  • Hello,

    I have available to me a netgate dual alix system.  If I get the second serial ports working, can I pass pfsync back and forth over them?  Will I need to enable PPP on the ports to do it?  For that matter, if I manage to get ppp working in freebsd, will the ppp interfaces appear in the gui?


  • Rebel Alliance Developer Netgate

    No, that won't work for a few reasons:

    • Not enough bandwidth over serial for that amount of data
    • Serial ports on ALIX are output-only for the console
    • It's a really bad idea.


    If you are low on ports, VLANs are great for getting around that limit.

  • Ok, Thanks!

    Just curious, do you know much data is actually transferred with pfsync?  Or more specifically, what is the minimum data rate needed?

    As to the output only status of the serial ports: Actually on the alix 2D13 boards, there is a second serial port header on the board, so in theory the console port is still in use as a console port!  I suppose gpib could also be used, but I just went off of the deep end there…


  • Rebel Alliance Developer Netgate

    The data rate for pfsync depends on your network load. It sends data for every state insertion/deletion/etc. I'm not sure how representative this is of a typical cluster, but I just checked one that is front of a couple servers (web, mail, etc, etc) and it averages about 400Kbps, peaked at around 800Kbps. Over the course of a day it transferred just over 3GB of data on the interface.

    And that's on a box that only averages around 5k states.

  • Wow.  Thanks!  Ok, I am happy!  Thank you for your information!

Log in to reply