3CX backups to an FTP server fail

[SuperTima]

Hi guys,
I have a weird issue when none of our customers 3CX instances back up to an on-prem FTP server.
It could be something on our side, but I just wanted to confirm that 3CX supports FTP passive mode?
Thanks, Tim.

 

[SuperTima]

Hi guys,
I have a weird issue when none of our customers 3CX instances back up to an on-prem FTP server.
It could be something on our side, but I just wanted to confirm that 3CX supports FTP passive mode?
Thanks, Tim.

Update.
We can now confirm that our FTP server works flawlessly in passive mode - FTP clients can download and upload data with no problems.
The 3CX backups to FTP DO NOT work, so it is an issue on the 3CX side.
The 3CX instance establishes the FTP connection successfully and within the first 3-4 seconds we get this -
229 Entering Extended Passive Mode (|||10140|)* (* port number can be anything between 10100 and 10199 - this is the range we used for passive mode as per 3CX recommendations) - and then this - QUIT and 221 Goodbye.
I know that previous versions of 3CX did not support Extended Passive Mode - is that still an issue with v. 18?
Please help.
Thanks.

 

[VasilisV_3CX]

Hi @SuperTima,

Can you confirm that the port range 10100 and 10199 is indeed open on the FTPs end?

Can you run a packet capture on the PBX and make sure that the PBX is sending the request traffic on the port provided by the FTP server?

What FTP server are you using?

 

[SweetAction]

It might be the old FTP timeout issue. See here: https://www.3cx.com/community/threa...if-call-history-is-selected.59897/post-252144

 

[SuperTima]

Thanks for your replies, guys.
We are using FileZilla FTP server (the latest version).
I have not had a chance to run packet capture yet, will do that tonight or tomorrow and will let you guys know.
Thanks!
Tim.

 

[VasilisV_3CX]

Thanks @SuperTima, feel free to PM me the capture when you have it.

 

[NickD_3CX]

We double-checked this with a Local V16 Update 8 3CX installation backing up to a Local Filezilla Server and it seems to working fine in Extended Passive Mode:


Send the log to @VasilisV_3CX in case we can spot something out of the ordinary.

 

[SuperTima]

It might be the old FTP timeout issue. See here: https://www.3cx.com/community/threa...if-call-history-is-selected.59897/post-252144

Hi Vasilis,
No, it's definitely not a time out issue as I have it set to 10 minutes (but the connection terminates within 15-20 seconds):

(000001)9/08/2021 13:59:20 PM - (not logged in) (54.xxx.xxx.121)> Connected on port 21, sending welcome message...
(000001)9/08/2021 13:59:20 PM - (not logged in) (54.xxx.xxx.121)> USER 3cx_ace
(000001)9/08/2021 13:59:20 PM - (not logged in) (54.xxx.xxx.121)> 331 Password required for 3cx_ace
(000001)9/08/2021 13:59:20 PM - (not logged in) (54.xxx.xxx.121)> PASS *****************
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> 230 Logged on
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> FEAT
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> 211-Features:
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> MDTM
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> REST STREAM
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> SIZE
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> MLST type*;size*;modify*;
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> MLSD
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> UTF8
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> CLNT
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> MFMT
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> EPSV
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> EPRT
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> 211 End
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> OPTS UTF8 ON
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> 202 UTF8 mode is always enabled. No need to send this command.
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> SYST
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> 215 UNIX emulated by FileZilla
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> QUIT
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> 221 Goodbye
(000001)9/08/2021 13:59:20 PM - 3cx_ace (54.xxx.xxx.121)> disconnected.
(000002)9/08/2021 13:59:21 PM - (not logged in) (54.xxx.xxx.121)> Connected on port 21, sending welcome message...
(000002)9/08/2021 13:59:21 PM - (not logged in) (54.xxx.xxx.121)> USER 3cx_ace
(000002)9/08/2021 13:59:21 PM - (not logged in) (54.xxx.xxx.121)> 331 Password required for 3cx_ace
(000002)9/08/2021 13:59:21 PM - (not logged in) (54.xxx.xxx.121)> PASS *****************
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> 230 Logged on
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> FEAT
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> 211-Features:
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> MDTM
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> REST STREAM
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> SIZE
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> MLST type*;size*;modify*;
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> MLSD
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> UTF8
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> CLNT
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> MFMT
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> EPSV
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> EPRT
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> 211 End
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> OPTS UTF8 ON
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> 202 UTF8 mode is always enabled. No need to send this command.
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> SYST
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> 215 UNIX emulated by FileZilla
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> TYPE I
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> 200 Type set to I
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> EPSV
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> 229 Entering Extended Passive Mode (|||10116|)
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> MLSD /
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> 150 Opening data channel for directory listing of "/"
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> 226 Successfully transferred "/"
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> QUIT
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> 221 Goodbye
(000002)9/08/2021 13:59:21 PM - 3cx_ace (54.xxx.xxx.121)> disconnected.

I will send you the .pcap file in a minute.

Mind you - we have 15+ other FTP clients configured on the same server, and all of them successfully transfer data - and we only had ports 20 and 21 opened in our firewall in order to configure them.

Thanks!
Tim

 

[SuperTima]

Thanks @SuperTima, feel free to PM me the capture when you have it.

--EDITED--

 

[ChrisC_3CX]

@SuperTima

I'll PM you shortly regarding this case.