Load the tftp server and the firmware on your local box. Then you "should" be able to find a setting on the zoom to set the tftp server address. In this case, you would set the tftp server address (in the zoom) to the address of your local box (where the tftp server is running).

Since, hopefully both your local box and the zoom will be on the same network (your private lan) they should be able to find and communicate with each other with a minimum of fuss and bother.

Hope this helps.

Norm