2. Can the file be split across packets?
Yes, a file can be split across packets. The switch is setting data size by packet.

3. If you are trying to move a file that is large "ish" in terms of packet size isn't this going to be affected by some router's MTU settings for example or will HPing deal with any packet fragmentation?
No, because you can certainly control MTU with HPING.



Perhaps I should reword that section...