Invalid FTP Response (B0)


#1

I can not connect with the ftp server. All parameters are ok but this is the error I gettting testing ftp conection:

[DST-2:1201#3] Failed to initialize the destination test. > Invalid FTP response (B0).

This is the log:


#2

Hello,

Could you please try to upload a backup file to that folder via Rebex FTP Test Client https://www.dropbox.com/s/rsnf5o0y4uhyld5/RebexFtpClient.zip?dl=0


#3

Hello,
I have done the test using cuteftp and filezilla ftp clients without error.

I have checked with Rebex FTP cliente and I have reproduced the error. To reproduce the error you must connect, go into the target folder and back again to the root folder (pushing on “…”) .
I suppose your software is doing something like that because the error is exactly the same. This is the log:


#4

Sorry:
This is the log, previous not:

Welcome to Rebex FTP!
16:06:46.558 Info Info: Connecting to ftp.xxxxxx.com:21 using Ftp.
16:06:46.558 Info Info: Assembly: Rebex.Ftp 2017 R3 for .NET 4.0-4.7
16:06:46.562 Info Info: Using proxy none.
16:06:46.754 Info Response: 220 XXXXX FTP XXX. Host: XXXXXX
16:06:46.794 Info Command: USER XXXXXXX
16:06:46.873 Info Response: 331 Username OK, need password
16:06:46.877 Info Command: PASS ***********
16:06:46.957 Info Response: 230 Welcome Departamento
16:06:46.961 Info Command: FEAT
16:06:47.041 Info Response: 211-Supported commands:
16:06:47.041 Info Response: AUTH TLS
16:06:47.041 Info Response: PBSZ
16:06:47.041 Info Response: PROT
16:06:47.041 Info Response: SIZE
16:06:47.041 Info Response: MDTM
16:06:47.041 Info Response: OPTS
16:06:47.041 Info Response: UTF8
16:06:47.041 Info Response: MFMT
16:06:47.041 Info Response: MLSD
16:06:47.041 Info Response: MLST type*;size*;modify*;unix.mode;
16:06:47.041 Info Response: 211 end
16:06:47.053 Info Command: OPTS UTF8 ON
16:06:47.134 Info Response: 202 UTF8 mode is always enabled. No need to send this command
16:06:47.138 Info Command: OPTS MLST type;size;modify;unix.mode;
16:06:47.222 Info Response: 200 MLST OPTS type;size;modify;unix.mode;
16:06:47.273 Info Command: TYPE A
16:06:47.353 Info Response: 200 TYPE is now A
16:06:47.365 Info Command: PASV
16:06:47.446 Info Response: 227 Entering Passive Mode (82,129,64,220,16,195)
16:06:47.534 Info Command: MLSD
16:06:47.616 Info Response: 150 Data connection established
16:06:47.634 Info Response: 226 Directory listing complete
16:06:47.678 Info Command: PWD
16:06:47.867 Info Response: 257 “/” is current directory
16:06:49.723 Info Command: CWD WINXXX
16:06:49.801 Info Response: 250 CWD successful. “/WINXXX” is current directory.
16:06:49.805 Info Command: PASV
16:06:49.883 Info Response: 227 Entering Passive Mode (82,129,64,220,17,181)
16:06:49.959 Info Command: MLSD
16:06:50.039 Info Response: 150 Data connection established
16:06:50.216 Info Response: 226 Directory listing complete
16:06:50.395 Info Command: PWD
16:06:50.473 Info Response: 257 “/WINXXX” is current directory
16:06:52.662 Info Command: CDUP
16:06:52.742 Info Response: 200 “/” is current directory.
16:06:52.754 Info Command: PASV
16:06:52.758 Info Response:
16:06:52.766 Error Info: Rebex.Net.FtpException: Invalid FTP response (B0).
en Rebex.Net.ONG.KZ(Int32 C)
en Rebex.Net.Ftp.DX(Int32 C, Boolean V)
en Rebex.Net.Ftp.GU()
en Rebex.Net.Ftp.QU(String C, Boolean V, KSG Z, IQ N, Int64 Q, FtpTransferState M)
en Rebex.Net.Ftp.ZL(String C, Boolean V, Stream Z, Int64 N, String Q, IQ M)
16:06:52.766 Error Info: Rebex.Net.FtpException: Invalid FTP response (B0).
en Rebex.Net.ONG.KZ(Int32 C)
en Rebex.Net.Ftp.DX(Int32 C, Boolean V)
en Rebex.Net.Ftp.GU()
en Rebex.Net.Ftp.QU(String C, Boolean V, KSG Z, IQ N, Int64 Q, FtpTransferState M)
en Rebex.Net.Ftp.ZL(String C, Boolean V, Stream Z, Int64 N, String Q, IQ M)

  • System.AggregateException: Se han producido uno o varios errores. —> Rebex.Net.FtpException: Invalid FTP response (B0).
    en Rebex.Net.ONG.KZ(Int32 C)
    en Rebex.Net.Ftp.DX(Int32 C, Boolean V)
    en Rebex.Net.Ftp.GU()
    en Rebex.Net.Ftp.QU(String C, Boolean V, KSG Z, IQ N, Int64 Q, FtpTransferState M)
    en Rebex.Net.Ftp.ZL(String C, Boolean V, Stream Z, Int64 N, String Q, IQ M)
    en Rebex.Net.Ftp.KL(String C, IQ V)
    en Rebex.Net.Ftp.BB(Object C, Enum V, Object[] Z)
    en Rebex.WW.ZV(Object C)
    — Fin del seguimiento de la pila de la excepción interna —
    en Rebex.Samples.MainForm.MakeFtpList() en C:\Users\passm\OneDrive\Документы\Rebex Components 2017 R3 - Samples\vs2012-net-4.0\Ftp\FtpWinFormClientClassic_CS\MainForm.cs:línea 471
    —> (Nº de excepción interna 0) Rebex.Net.FtpException: Invalid FTP response (B0).
    en Rebex.Net.ONG.KZ(Int32 C)
    en Rebex.Net.Ftp.DX(Int32 C, Boolean V)
    en Rebex.Net.Ftp.GU()
    en Rebex.Net.Ftp.QU(String C, Boolean V, KSG Z, IQ N, Int64 Q, FtpTransferState M)
    en Rebex.Net.Ftp.ZL(String C, Boolean V, Stream Z, Int64 N, String Q, IQ M)
    en Rebex.Net.Ftp.KL(String C, IQ V)
    en Rebex.Net.Ftp.BB(Object C, Enum V, Object[] Z)
    en Rebex.WW.ZV(Object C)<—

#5

Thank you for the details, please give us some time to check it.


#6

Hello,

Could you please install the latest version of SQLBackupAndFTP - version 11.1.22 and check if it solves that issue?


#7

I’m using this version: 11.1.22


#8

Hi,
could you investigate something about this issue?


#9

Hi,

Currently, we are working to solve this issue and it will be fixed in the next release in 2-3 days.

Sorry for the inconvenience.


#10

Hello,

We have just released SQLBackupAndFTP 11.2.1 with updated FTP destination:

  1. Speed of uploading to FTP destination increased up to 60%
  2. More FTP advanced settings:
    2.1. Connect passive later: Makes the passive mode transfer initialize the connection only after the LIST/NLST/RETR/STOR command has been sent.
    2.2. Disable invalid passive mode address workaround: Disables a workaround for FTP servers that announce private range IP addresses even though a public IP was used to connect to them. By default, when such server is detected, an IP address announced by the server in response to PASV command used is overrode with an IP used by the control connection.
    2.3. Enable control connection flushing: Enables reading and throwing out any unexpected incoming responses when sending an FTP command.
    2.4. Pause before upload close: Performs a small pause before closing the encrypted upload connection when the transfer is finished. Used as a workaround for servers that are unable to correctly handle the last block data if it is followed by a TLS CloseNotify message in the same TCP block.
    2.5. Use large buffers: Use larger receive buffer for incoming and outgoing data.

Could you please update SQLBackupAndFTP application to the latest release and check if you can upload your backup files with these new FTP options?
Thank you!


#11

Hi,
The error is exactly the same with the new version :frowning:

Destination error: Invalid FTP response (B0).
Trying again…
Destination error: Already connected to the server.

I have another old licensed version in other server, but I can not migrate due to this issue


#12

Thank you for the feedback. Please give us some time to check it.

Sorry for the inconvenience.


#13

Hi Alexander,
Some news about this issue? If it is not fixed i will have to use the old version

Regards


#14

Hello,

Please try to use FTP destination with “Enable control connection flushing” option.
To enable this option, open your FTP destination settings, click “Advanced FTP Settings” link, then click “Even more FTP Settings” link and find “Enable control connection flushing” option at “More FTP Settings” window.


Regards,
Alexey


#15

Hello,
The error is the same with “Enable control connectionflushing” option enabled


#16

Hello,

It seems we cannot solve this issue with the help of SQLBackupAndFTP.

SQLBackupAndFTP sends a command to your server that it is needed to switch to passive mode, but your FTP Server responds with an empty row - which is violations.

16:06:52.754 Info Command: PASV
16:06:52.758 Info Response:

Your FTP Server should respond that it is switched to a passive mode or send an error.

Also, you can try to enable “Connect passive later” option and check if it solves the issue. To enable this option, open your FTP destination settings, click “Advanced FTP Settings” link, then click “Even more FTP Settings” link and find “Connect passive later” option at “More FTP Settings” window.


#17

Hello,

I have send your response to ftp system admins.

How can install previous version (10 I think) ? We had not any trouble with this version


#18

Hello,

You can download SQLBackupAndFTP version 10 by the following link https://sqlbackupandftp.com/download/SqlBakSetupAzure.exe


#19

Hello,
Development from my ftp server service (livedrive.com) ask me if I could provide more information about your connection type, if you could provide the exact settings you have in place it will help them with being able to try and replicate this issue in office.

Could you give me this information?

Thank you


#20

Hello,

We use Rebex ftp .net library to connect to FTP.

Connection type, active\passive mode and other settings you can find in the “Advanced FTP Settings”.

Also, you can enable log, run a backup job and then check the log file. There you can find all responses and requests for FTP.

Sorry for the inconvenience.