The thing now is, who is initiating the data connection? Is it whfc,
which has connected successfully and now wants the data, too? - This
should work.
If whfc is set to use passive, then the server tells the client which
additional port connect to. This port will have to be forwarded and I
don't know what port range it will be in. Normally with FTP its
completely random, hylafax might be doing the same. Just forwarding 20
and 21 won't work.
Someone on the list with more knowledge of the protocol might be able
to answer; otherwise you'll have to tcpdump the network to see what
ports are being used.
Now if the client you're using is exposed to the internet, then active
FTP should work, as the server will connect back to your client
computer on the specified port. If your client computer can't accept
incoming connections either, then you're back at passive trying to
forward the proper ports.
--
Steven Kurylo
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