Existing connection was forciby closed by the remote host

Question

I have a program which uses Rebex to connect to an FTP site, check each file against local files, and download the files which have been updated. The program has been in use for over four years at several different locations. Just today at one location the users are getting the error listed in the title. There are multiple computers at that location and all are getting the error. Meanwhile at other locations the program is executing with no errors. I tried adding several different options to the program such as KeepAlive, Options=DoNotDetectFeatures, etc. but they are still getting the error. Below is the log that was generated:

    2011-15-11 11:12:37.518 Opening log file.
2011-15-11 11:12:37.596 INFO Ftp(1) Info: Connecting to cnhs.host-ed.net:21 using Ftp 3.0.3300.0.
2011-15-11 11:12:37.596 INFO Ftp(1) Info: Using proxy none.
2011-15-11 11:12:37.940 DEBUG Ftp(1) Info: Connection succeeded.
2011-15-11 11:12:37.986 INFO Ftp(1) Response: 220 ::ffff:82.197.130.24 FTP server ready
2011-15-11 11:12:37.986 INFO Ftp(1) Command: USER 213522_user
2011-15-11 11:12:38.158 INFO Ftp(1) Response: 331 Password required for 213522_user
2011-15-11 11:12:38.158 INFO Ftp(1) Command: PASS ********
2011-15-11 11:12:38.314 INFO Ftp(1) Response: 230 Welcome to your web hosting account!Please upload your web site inside the directory of the respective hostname.(If you wish to upload outside the hostname directories or delete them please make sure Directory Protection is set to OFF from your hosting control panel - File Manager section)
2011-15-11 11:12:38.314 INFO Ftp(1) Command: FEAT
2011-15-11 11:12:38.471 INFO Ftp(1) Response: 211-Features:
2011-15-11 11:12:38.471 INFO Ftp(1) Response:  MDTM
2011-15-11 11:12:38.471 INFO Ftp(1) Response:  MFMT
2011-15-11 11:12:38.471 INFO Ftp(1) Response:  TVFS
2011-15-11 11:12:38.471 INFO Ftp(1) Response:  MFF modify;UNIX.group;UNIX.mode;
2011-15-11 11:12:38.471 INFO Ftp(1) Response:  MLST modify*;perm*;size*;type*;unique*;UNIX.group*;UNIX.mode*;UNIX.owner*;
2011-15-11 11:12:38.471 INFO Ftp(1) Response:  REST STREAM
2011-15-11 11:12:38.471 INFO Ftp(1) Response:  SIZE
2011-15-11 11:12:38.471 INFO Ftp(1) Response: 211 End
2011-15-11 11:12:38.486 DEBUG Ftp(1) Info: Starting data transfer.
2011-15-11 11:12:38.486 INFO Ftp(1) Command: TYPE A
2011-15-11 11:12:38.658 INFO Ftp(1) Response: 200 Type set to A
2011-15-11 11:12:38.658 INFO Ftp(1) Command: PASV
2011-15-11 11:12:38.814 INFO Ftp(1) Response: 227 Entering Passive Mode (82,197,130,24,192,87).
2011-15-11 11:12:38.814 DEBUG Ftp(1) Info: Establishing data connection.
2011-15-11 11:12:39.001 INFO Ftp(1) Command: MLSD
2011-15-11 11:12:39.173 INFO Ftp(1) Response: 150 Opening ASCII mode data connection for MLSD
2011-15-11 11:12:39.189 DEBUG Ftp(1) Info: Data transfer ended.
2011-15-11 11:12:39.189 DEBUG Ftp(1) Info: Closing downloading data connection.
2011-15-11 11:12:39.189 DEBUG Ftp(1) Info: Waiting for data transfer ending message.
2011-15-11 11:12:39.345 INFO Ftp(1) Response: 226 Transfer complete
2011-15-11 11:12:39.345 DEBUG Ftp(1) Info: Data transfer ended.
2011-15-11 11:12:39.345 DEBUG Ftp(1) Info: Transfer ended successfully.
2011-15-11 11:12:39.345 DEBUG Ftp(1) Info: Data connection closed.
2011-15-11 11:12:39.345 INFO Ftp(1) Command: CWD /Reports
2011-15-11 11:12:39.501 INFO Ftp(1) Response: 250 CWD command successful
2011-15-11 11:12:39.501 INFO Ftp(1) Command: PWD
2011-15-11 11:12:39.673 INFO Ftp(1) Response: 257 "/Reports" is the current directory
2011-15-11 11:12:39.673 DEBUG Ftp(1) Info: Starting data transfer.
2011-15-11 11:12:39.673 INFO Ftp(1) Command: PASV
2011-15-11 11:12:39.829 INFO Ftp(1) Response: 227 Entering Passive Mode (82,197,130,24,192,160).
2011-15-11 11:12:39.829 DEBUG Ftp(1) Info: Establishing data connection.
2011-15-11 11:12:40.001 INFO Ftp(1) Command: MLSD
2011-15-11 11:12:40.141 INFO Ftp(1) Response: 150 Opening ASCII mode data connection for MLSD
2011-15-11 11:12:40.157 DEBUG Ftp(1) Info: Data transfer ended.
2011-15-11 11:12:40.157 DEBUG Ftp(1) Info: Closing downloading data connection.
2011-15-11 11:12:40.157 DEBUG Ftp(1) Info: Waiting for data transfer ending message.
2011-15-11 11:12:40.313 INFO Ftp(1) Response: 226 Transfer complete
2011-15-11 11:12:40.313 DEBUG Ftp(1) Info: Data transfer ended.
2011-15-11 11:12:40.313 DEBUG Ftp(1) Info: Transfer ended successfully.
2011-15-11 11:12:40.313 DEBUG Ftp(1) Info: Data connection closed.
2011-15-11 11:12:40.313 INFO Ftp(1) Command: PWD
2011-15-11 11:12:40.469 INFO Ftp(1) Response: 257 "/Reports" is the current directory
2011-15-11 11:12:40.469 INFO Ftp(1) Command: CWD /Reports/Payables
2011-15-11 11:12:40.626 INFO Ftp(1) Response: 250 CWD command successful
2011-15-11 11:12:40.626 INFO Ftp(1) Command: PWD
2011-15-11 11:12:40.797 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:40.797 DEBUG Ftp(1) Info: Starting data transfer.
2011-15-11 11:12:40.797 INFO Ftp(1) Command: PASV
2011-15-11 11:12:40.969 INFO Ftp(1) Response: 227 Entering Passive Mode (82,197,130,24,192,89).
2011-15-11 11:12:40.969 DEBUG Ftp(1) Info: Establishing data connection.
2011-15-11 11:12:41.125 INFO Ftp(1) Command: MLSD
2011-15-11 11:12:41.266 INFO Ftp(1) Response: 150 Opening ASCII mode data connection for MLSD
2011-15-11 11:12:41.281 DEBUG Ftp(1) Info: Data transfer ended.
2011-15-11 11:12:41.281 DEBUG Ftp(1) Info: Closing downloading data connection.
2011-15-11 11:12:41.281 DEBUG Ftp(1) Info: Waiting for data transfer ending message.
2011-15-11 11:12:41.422 INFO Ftp(1) Response: 226 Transfer complete
2011-15-11 11:12:41.422 DEBUG Ftp(1) Info: Data transfer ended.
2011-15-11 11:12:41.422 DEBUG Ftp(1) Info: Transfer ended successfully.
2011-15-11 11:12:41.422 DEBUG Ftp(1) Info: Data connection closed.
2011-15-11 11:12:41.438 INFO Ftp(1) Command: PWD
2011-15-11 11:12:41.578 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:41.578 INFO Ftp(1) Command: PWD
2011-15-11 11:12:41.734 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:41.734 INFO Ftp(1) Command: PWD
2011-15-11 11:12:41.890 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:41.890 INFO Ftp(1) Command: PWD
2011-15-11 11:12:42.047 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:42.047 INFO Ftp(1) Command: PWD
2011-15-11 11:12:42.203 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:42.203 INFO Ftp(1) Command: PWD
2011-15-11 11:12:42.343 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:42.343 INFO Ftp(1) Command: PWD
2011-15-11 11:12:42.500 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:42.500 INFO Ftp(1) Command: PWD
2011-15-11 11:12:42.656 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:42.656 INFO Ftp(1) Command: PWD
2011-15-11 11:12:42.796 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:42.796 INFO Ftp(1) Command: PWD
2011-15-11 11:12:42.952 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:42.952 INFO Ftp(1) Command: PWD
2011-15-11 11:12:43.109 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:43.109 INFO Ftp(1) Command: PWD
2011-15-11 11:12:43.249 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:43.249 INFO Ftp(1) Command: PWD
2011-15-11 11:12:43.405 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:43.405 INFO Ftp(1) Command: PWD
2011-15-11 11:12:43.546 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:43.561 INFO Ftp(1) Command: PWD
2011-15-11 11:12:43.702 INFO Ftp(1) Response: 257 "/Reports/Payables" is the current directory
2011-15-11 11:12:43.702 INFO Ftp(1) Command: PWD
2011-15-

Comments

Hello, the log indicates that Rebex FTP was able to successfully download "PaperBill.rpt" and "PrintCheckForPatient.rpt" files, but failed on "Receivables.zip" file. So at least some downloads are working at that location. Does it always fail at the same file, or are the failures random?

Answer 1

Thank you so much for your response. It seems like the failure is always at the same file (which is significantly larger than the files that downloaded successfully). The IT department has been working on some issues, I'm not sure specifically what, and have successfully resolved the problem (at least for now). When they are finished I will try to find out what they did and post it here in case it can help someone else. Again, I really appreciate your response.

Comments

Thanks! This really looks like a server issue then. To make sure, try downloading the file using a third-party FTP client such as Filezilla. If you get a similar error, it would be a proof. Let is know if you find out what's going on, others might find it useful as well.

---

The IT dept. says that they loosened some of the settings on the firewall. All files are going thru now. They were originally erroring out when trying to download thru Firefox as well, as stated in my initial post, and that combined with the fact that the IT dept fixed it by changing firewall settings leads me to conclude it was a security issue and nothing to do with Rebex. Hope this helps someone else. Thanks for looking at the problem. Have a great day!

---

Thanks for letting us know! It is quite interesting that a firewall settings can cause a specific file (or perhaps group of files) to become non-downloadable. Looks like a misconfigured content-aware FTP firewall. By the way, the following document might be useful for those dealing with similar issues who need to understand the underlying protocol: http://www.ford-hutchinson.com/~fh-1-pfh/draft-fordh-ftp-ssl-firewall-07.txt