>> Monitor the network activity from the begining of transmition until stuck
>> condition, and analyze the whole transaction throughoutly with care,
>> especially at the end.
>
> Monitor with what? A sniffer? What am I looking for?

In the case of no sniffer available, tcpdump(8) is a next candidate.   Check
points would be;

	- the content of BOOTP response.
	- initial conversion of TFTP transfer between two.
	- the very last incident when the TFTP client hits wall.
	- whether TFTP client is trying to continue a request or simple has
	  stopped in the middle of transaction.
	- the amount of TFTP data transfered until then.
	- size of TFTP transfer chunk (is it the negoniatable parameter? I'm
	  not sure)
	- others ...

Tohru Nishimura