3 Replies Latest reply on Nov 3, 2011 7:31 AM by mlake

    TFTP Server does not ACK



      I am trying to flash an Avocent DSR1021 switch and I have a TFTP server (SolarWinds) running on a laptop that is connected with a crossover cable directly to the switch (it communicates with a straight-through or crossover cable but I took the time to make the crossover so i left it plugged in.) I have the DSR1021.fl file the switch needs to recover itself in the root folder and I am using Wireshark to watch the traffic on the port that is only connected to the device. 

      The switch( is requesting to read the file it needs from the server(, but the server never answers or ACK. It is continuously broadcasting ARP for our AD server (the server was previously on our domain but it is connected to our public wifi now for this "rescue mission" because it doesn't need to be connected.

      What can I do to make the .3 answer back and give .2 the file?

      Thank you in advance!



        • Re: TFTP Server does not ACK


          Check the server binding settings on the TFTP server and make sure that your currently available addresses and your binding list match your expectations.  Then check your security settings and make sure that you are set to send and receive files and there are no restrictions set that might be blocking you.



            • Re: TFTP Server does not ACK

              Everything is currently set to bind with all IP addresses and everything is able to send and receive to and from all IP address. I even modified those settings to reflect the IP range that I needed under IP Restrictions, bound the interface ( to the server, and also bound all ip's so it would use all the addresses in the list. Still no result. I have been letting this machine stay hooked up (it's just sitting on a desk in my office) for the evening to run and It has never responded to the switch's Read request.

              • Re: TFTP Server does not ACK

                Additionally, for good practice, I would only make one change at a time and I would stop and start the service after each change I made.