Help doing FTPES

[Alphabetic]

18.0 (Build 418)

Good morning,

Im having some trouble setting up FTP for my backup location on 3CX.

I've set up a Filezilla server on Windows with the following config:









I can successfully connect to this Filezilla service via Filezilla off an external PC



From the PC:



3CX Config:

<Date> Info [Type] Message
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> [Response] 220-FileZilla Server 1.6.6
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> [Response] 220-Please visit https://filezilla-project.org/
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> [Response] 220 Welcome to your 3CX Archive!
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> [Command] AUTH TLS
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> [Response] 234 Using authentication type TLS.
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> [Command] USER <ftpusername>
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> [Response] 331 Please, specify the password.
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> [Command] PASS ****
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 230 Login successful.
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Command] PBSZ 0
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 200 PBSZ=0
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Command] PROT P
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 200 Protection level set to P
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Command] FEAT
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 211-Features:
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 211 End
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Command] OPTS UTF8 ON
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 202 UTF8 mode is always enabled. No need to send this command
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Command] SYST
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 215 UNIX emulated by FileZilla.
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Command] PWD
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 257 "/" is current directory.
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Command] CWD /Backup
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 250 CWD command successful
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Command] CWD /
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 250 CWD command successful
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Command] QUIT
<06-02-2023 09:05:02> FTP Session 13 <3CXWANIP> <ftpusername> [Response] 221 Goodbye.
<06-02-2023 09:05:02> FTP Server [Status] Session 13 ended gracefully.
<06-02-2023 09:05:02> FTP Session 14 <3CXWANIP> [Response] 220-FileZilla Server 1.6.6
<06-02-2023 09:05:02> FTP Session 14 <3CXWANIP> [Response] 220-Please visit https://filezilla-project.org/
<06-02-2023 09:05:02> FTP Session 14 <3CXWANIP> [Response] 220 Welcome to your 3CX Archive!
<06-02-2023 09:05:02> FTP Session 14 <3CXWANIP> [Command] AUTH TLS
<06-02-2023 09:05:02> FTP Session 14 <3CXWANIP> [Response] 234 Using authentication type TLS.
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> [Command] USER <ftpusername>
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> [Response] 331 Please, specify the password.
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> [Command] PASS ****
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 230 Login successful.
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Command] PBSZ 0
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 200 PBSZ=0
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Command] PROT P
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 200 Protection level set to P
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Command] FEAT
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 211-Features:
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 211 End
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Command] OPTS UTF8 ON
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 202 UTF8 mode is always enabled. No need to send this command
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Command] SYST
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 215 UNIX emulated by FileZilla.
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Command] TYPE I
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 200 Type set to I
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Command] EPSV
<06-02-2023 09:05:03> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 229 Entering Extended Passive Mode (|||49171|)
<06-02-2023 09:05:04> FTP Session 14 <3CXWANIP> <ftpusername> [Command] MLSD /Backup
<06-02-2023 09:05:04> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 150 Starting data transfer.
<06-02-2023 09:05:04> FTP Session 14 <3CXWANIP> <ftpusername> [Error] TLS session of data connection not resumed.
<06-02-2023 09:05:04> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 425 Unable to build data connection: TLS session of data connection not resumed.
<06-02-2023 09:05:04> FTP Session 14 <3CXWANIP> <ftpusername> [Command] QUIT
<06-02-2023 09:05:04> FTP Session 14 <3CXWANIP> <ftpusername> [Response] 221 Goodbye.
<06-02-2023 09:05:04> FTP Server [Status] Session 14 ended gracefully.

Any advice appreciated

 

[Lee Cramman]

I'm a bit rusty with FTP but I think 425 errors are caused by the port range used for passive transfers not being allowed. The port is open for the client / server to communicate / initiate transfers but they can't open a port for the transfer to take place.

That could be caused a port forwarding or a firewall issue but if there is an external network / router involved that's where I would look first.

Have a read of this: https://wiki.filezilla-project.org/Setting_up_your_Router_to_Fix_the_"425_code"

 

[Alphabetic]

I'm a bit rusty with FTP but I think 425 errors are caused by the port range used for passive transfers not being allowed. The port is open for the client / server to communicate / initiate transfers but they can't open a port for the transfer to take place.

That could be caused a port forwarding or a firewall issue but if there is an external network / router involved that's where I would look first.

Have a read of this: https://wiki.filezilla-project.org/Setting_up_your_Router_to_Fix_the_"425_code"

I've doublechecked and the firewall is correct.

I believe it's something to do with 3CX not accepting the warning to use the self signed certificate on the FTP server so it goes no further.

 

[Lee Cramman]

I've doublechecked and the firewall is correct.

I believe it's something to do with 3CX not accepting the warning to use the self signed certificate on the FTP server so it goes no further.

I would have expected that to arise at the initial authentication though. I would also have expected a log entry to that effect.

Why not try SSH'ing on and manually connecting to the FTP server to see what happens and what warnings / errors you get client side when you try to initiate a transfer?

It might give some valuable clues.

Also, I know I'm probably teaching my grandmother how to suck eggs but... is Windows firewall enabled?

 

[OibafA]

Hi! FileZilla Server developer here, not really a 3CX customer, but just chiming in to shed light on the issue.

The reason for the 425 error is actually given on the very line the error itself is given, rendered in bold in the following quote: "425 Unable to build data connection: TLS session of data connection not resumed."

That means that FileZilla Server expects the client to use for the data connection a TLS session that is resumed from the one used for the control connection (the "control connection" being the connection over which the FTP commands go). This is a measure that is necessary to ensure that the connection is really secure.

The 3CX client must be updated to make this possible.

For further info: https://forum.filezilla-project.org/search.php?keywords=TLS+resumption

 

[Alphabetic]

Hi! FileZilla Server developer here, not really a 3CX customer, but just chiming in to shed light on the issue.

The reason for the 425 error is actually given on the very line the error itself is given, rendered in bold in the following quote: "425 Unable to build data connection: TLS session of data connection not resumed."

That means that FileZilla Server expects the client to use for the data connection a TLS session that is resumed from the one used for the control connection (the "control connection" being the connection over which the FTP commands go). This is a measure that is necessary to ensure that the connection is really secure.

The 3CX client must be updated to make this possible.

For further info: https://forum.filezilla-project.org/search.php?keywords=TLS+resumption

thanks for this, i'll pass it on.

I thought that maybe it was that 3CX ftp client wasnt/couldnt accept the self signed certificate from the Filezilla server.

 

[flexserve]

thanks for this, i'll pass it on.

I thought that maybe it was that 3CX ftp client wasnt/couldnt accept the self signed certificate from the Filezilla server.

Any resolution to this issue? I am using a DV cert I purchased. As noted, FileZilla client works perfectly both local LAN (to ftp server) and remote, though it connects PASV instead of EPSV.