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RE: Keeping Control Connection Alive

General Turgidson — Wed, 21 Nov 2007 16:28:48 GMT

Ipswitch may be interested to know that a general Google search for the term "The connection is probably dead" brought this thread up as the number one result. You might get a few sales out of getting a decent answer in here.

I'm having the same problem with WS_FTP PRO (registered) and I am not transferring a massive file...just 250 Kb (yes, Kb). The transfer seems to stop after just 58 k, thinking itself complete. The connection is not dead because I can still see the target site in FTP Pro, and I can do the transfer manually, as well as other commands. This is a scheduled task however, and needs to run on its own. The task executes; the transfer does not.

Here's the log:

Connecting to <target IP numbers>
Connected to <target IP numbers> in 0.375002 seconds, Waiting for Server Response
220-Microsoft FTP Service
220 RTIX Online FTP Service
Host type (1): Automatic Detect
USER TARGETFTP
331 Password required for TARGETFTP.
PASS (hidden)
230 User TARGETFTP logged in.
SYST
215 Windows_NT
Host type (2): Microsoft NT
Sending "FEAT" command to determine what features this server supports.
FEAT
211-FEAT
SIZE
MDTM
211 END
Finished interpreting "FEAT" response.
Sending the FEAT command is optional. You can disable it in the site options of the profile.
PWD
257 "/TARGETFTP" is current directory.
CWD /TARGETFTP
250 CWD command successful.
PWD
257 "/TARGETFTP" is current directory.
TYPE A
200 Type set to A.
PASV
227 Entering Passive Mode <target IP numbers>.
connecting data channel to <target IP numbers>
data channel connected to <target IP numbers>
LIST
125 Data connection already open; Transfer starting.
# transferred 58 bytes in < 0.001 seconds, 453.125 Kbps ( 56.641 Kbps), transfer succeeded.
226 Transfer complete.
QUIT
Failed Sending Command. The connection is probably dead.
Dead connections are not restarted For "QUIT" commands.
Connection closed. Ready for next connection.

RE: Keeping Control Connection Alive

M$ — Tue, 20 Mar 2007 00:07:47 GMT

After every huge file download I would have to reconnect and this is not efficient by any means !!

RE: Keeping Control Connection Alive

M$ — Tue, 20 Mar 2007 00:00:27 GMT

How does a legacy FTP Client like DOS can handle this ?

RE: Keeping Control Connection Alive

Claudio Robles — Mon, 19 Mar 2007 23:55:28 GMT

No, the SDK does not have an option to keep the control connection alive while transferring. However, your transfers seems to be succeeding, the failure is after that, when quitting which is usually not a big deal.

Claudio Robles
WS_FTP Team

Keeping Control Connection Alive

M$ — Tue, 13 Mar 2007 16:11:49 GMT

When trying to download huge files the control connetion seem to get terminated. Is there a way to keep it alive in SDK? Here is the log. DOS FTP Client works fine, that is , I get 221 REPLY CODE back after the download !!

Connecting to 63.78.143.254:21
Connected to 63.78.143.254:21 in 0.109379 seconds, Waiting for Server Response
220 Microsoft FTP Service
Host type (1): Automatic detect
USER solutions\ftp.uafc.rxcq.p
331 Password required for solutions\ftp.uafc.rxcq.p.
PASS (hidden)
230 User solutions\ftp.uafc.rxcq.p logged in.
SYST
215 Windows_NT
Host type (2): Microsoft NT
PWD
257 "/ftp.uafc.rxcq.p" is current directory.
Connection succeeedCWD /ftp.uafc.rxcq.p/pick_up
250 CWD command successful.
/ftp.uafc.rxcq.p/pick_up * loaded from [Directory Listing Cache]DIR10D.tmp
PWD
257 "/ftp.uafc.rxcq.p/pick_up" is current directory.
TYPE A
200 Type set to A.
PORT 10,1,109,241,11,105
200 PORT command successful.
LIST *
150 Opening ASCII mode data connection for /bin/ls.
# transferred 1998 bytes in 0.016 seconds, 998.955 Kbps ( 124.869 Kbps), transfer succeeded.
226 Transfer complete.
TYPE I
200 Type set to I.
PORT 10,1,109,241,11,109
200 PORT command successful.
RETR UAT_UAT_WK_ADD_TERM.TXT.OLD
150 Opening BINARY mode data connection for UAT_UAT_WK_ADD_TERM.TXT.OLD(39511808 bytes).
Transfer start, 39511808 bytes
Transfer finished, 39511808 bytes transferred
226 Transfer complete.
# transferred 39511808 bytes in 534.946 seconds, 577.042 Kbps ( 72.130 Kbps), transfer succeeded.
QUIT
Failed Sending Command. The connection is probably dead.

----------------------------DOS FTP CLIENT LOG------------------------------------------

ftp> get uat_uat_wk_add_term.txt.old
---> PORT 10,1,109,241,14,91
200 PORT command successful.
---> RETR uat_uat_wk_add_term.txt.old
150 Opening ASCII mode data connection for uat_uat_wk_add_term.txt.old(39511808
bytes).
226 Transfer complete.
ftp: 39511808 bytes received in 534.99Seconds 73.85Kbytes/sec.
ftp> bye
---> QUIT
221