I could believe that "quote pasv" prepares
the server for a passive transfer, but what
tells the client to initiate a passive
transfer? And if the client's not in passive
mode, how is it supposed to move a file to or
from a server which _is_ in passive mode?
Of course, I could just be venting methane,
but I believe that the client, when in
active mode, sends a PORT command to the
server to tell the server which address and
port number to use for the transfer, while in
passive mode, the client sends the server a
PASV command, and gets back the address and
port number to use (the server's preference).
You can do all of these that you wish using
the quote command, but, when it comes time to
do a put or get (STOR or RETR), the client
will do what it thinks is appropriate.
For a good time, in the VMS-to-VMS situation,
try a transfer before and after one of those
"quote pasv" commands. I believe that you'll
see no change in what happens in the
transfer. Use the (undocumented?) "debug"
command to see more. On my system:
alp $ ftp alp-l
220- Antinode FTP Server. Please be nice.
220 alp.antinode.org FTP Server (Version 5.4) Ready.
Connected to alp.
Name (alp:sms):
331 Username sms requires a Password
Password:
230 User logged in.
FTP> debug
Debugging on (debug=1).
FTP> get a.a q.q
---> TYPE I
200 TYPE set to IMAGE.
---> PORT 10,0,0,9,210,14
200 PORT command successful.
---> RETR a.a
150 Opening data connection for ALP$DKA0:[SMS]a.a; (10.0.0.9,53774) (4 bytes)
226 Transfer complete.
local: ALP$DKA0:[SMS]Q.Q;1 remote: a.a
4 bytes received in 00:00:00.01 seconds (0.39 Kbytes/s)
[Note that the client used a PORT command to
give the server an address and port number,
as it was not in passive mode.]
FTP> quote pasv
---> pasv
227 Entering Passive Mode (10,0,0,9,210,15)
[Looks good, but does nothing useful, I
claim. Observe the next transfer.]
FTP> get a.a p.p
---> PORT 10,0,0,9,210,16
200 PORT command successful.
---> RETR a.a
150 Opening data connection for ALP$DKA0:[SMS]a.a; (10.0.0.9,53776) (4 bytes)
226 Transfer complete.
local: ALP$DKA0:[SMS]P.P;1 remote: a.a
4 bytes received in 00:00:00.01 seconds (0.33 Kbytes/s)
[Note that the client _still_ uses a PORT
command here. It's still not thinking
passive.]
FTP> passive
_ON|OFF|AUTO|ALL: on
Passive is ON.
[_Now_ the client is thinking passive ...]
FTP> get a.a s.s
---> PASV
227 Entering Passive Mode (10,0,0,9,210,17)
---> RETR a.a
150 Opening data connection for ALP$DKA0:[SMS]a.a; (10.0.0.9,53778) (4 bytes)
226 Transfer complete.
local: ALP$DKA0:[SMS]S.S;1 remote: a.a
4 bytes received in 00:00:00.01 seconds (0.30 Kbytes/s)
[... and so this transfer included a PASV
command instead of a PORT command, and the
server's response provided the address and
port number for the client to use.]
FTP> quit
---> QUIT
221 Goodbye.
(In this case, the server and client both
had the same IP address, which could be a
bit confusing, unless you just ignore that
part, in which case, it's all harmless.)
So, as I said, you need to tell the client to
use passive mode. If your client can't do
passive mode, then you'll need to get a
better client. You can't get the client into
passive mode by manually sending ("quote") a
PASV command to the server.
Google did find this guide, which might be
useful:
http://www.ncftp.com/ncftpd/doc/misc/ftp_and_firewalls.htmland
http://slacksite.com/other/ftp.htmlAround here:
alp $ tcpip show version
HP TCP/IP Services for OpenVMS Alpha Version V5.4 - ECO 5
on a COMPAQ Professional Workstation XP1000 running OpenVMS V7.3-2
