Connection refused after entering passive mode

[MitsuTomoe]

Hi , I used to use Cyberduck to manage 2 ftp backup servers. For a while , I cannot connect to the 2nd one. I checked credentials to no avail. I tried with ForkLift application and I am able to connect without a hitch. Debug log file is attached.
Here I past ForkLift app log, maybe comparing with CyberDuck log might help ?
Hope this helps
Regards

22/04/2023 15:12:44 [dedibackup-dc3.online.net - 0] connected to 'dedibackup-dc3.online.net'
22/04/2023 15:12:44 [dedibackup-dc3.online.net - 0] 220 server ready - login please
22/04/2023 15:12:44 [dedibackup-dc3.online.net - 0] USER sd-100219
22/04/2023 15:12:44 [dedibackup-dc3.online.net - 0] 331 password required
22/04/2023 15:12:44 [dedibackup-dc3.online.net - 0] PASS **********
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0] 230 login accepted
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0] SYST
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0] 215 UNIX Type: L8
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0] FEAT
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0] 211-feature list follows
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0]  MDTM
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0]  SIZE
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0] 211 end
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0] PWD
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0] 257 "/" is your current location
22/04/2023 15:12:47 [dedibackup-dc3.online.net - 0] CWD /backup
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] 250 OK. Current directory is /backup
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] TYPE A
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] 200 TYPE is now ASCII
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] PASV
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] 227 Entering Passive Mode (62,210,18,29,241,83)
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] Server returned bogus IP address: 62.210.18.29 (should be: 62.210.18.68)
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] LIST -a
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] 150 Accepted data connection
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] drwxr-xr-x    1 1001       ftp                 0 Apr 22 12:56 archives
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] drwxr-xr-x    1 1001       ftp                 0 Apr 22 12:51 bases
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] drwxr-xr-x    1 1001       ftp                 0 Apr 22 12:52 serveur
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] drwxr-xr-x    1 1001       ftp                 0 Apr 22 12:56 sites
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] 226 4 matches total

cyberduck.log

[AliveDevil]

Your server configuration is faulty.
ForkLift works around this, by straight up ignoring a response, and continuing with what it assumes is correct.
Cyberduck handles server responses as authoritative, thus fails here:

22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] 227 Entering Passive Mode (62,210,18,29,241,83)
22/04/2023 15:12:48 [dedibackup-dc3.online.net - 0] Server returned bogus IP address: 62.210.18.29 (should be: 62.210.18.68)

The FTP server returns IP "62.210.18.29", which is not the server ForkLift connected to (62.210.18.68).

2023-04-22 15:04:04,499 [resolver-6] INFO  ch.cyberduck.core.Resolver - Resolved dedibackup-dc3.online.net to 62.210.18.68
…
2023-04-22 15:04:05,412 [Thread-63] INFO  ch.cyberduck.transcript.request - PASV
2023-04-22 15:04:05,428 [Thread-63] INFO  ch.cyberduck.transcript.response - 227 Entering Passive Mode (62,210,18,29,249,231)

Please reach out to your server provider and let them know that the passive IP of "dedibackup-dc3" has a wrong configuration.

[dkocher]

The log shows that the hostname is resolved to 62.210.18.68

2023-04-22 15:04:04,499 [resolver-6] INFO  ch.cyberduck.core.Resolver - Resolved dedibackup-dc3.online.net to 62.210.18.68

For PASV the server returns the address 62.210.18.29 to connect to is returned.

2023-04-22 15:04:05,412 [Thread-63] INFO  ch.cyberduck.transcript.request - PASV
2023-04-22 15:04:05,428 [Thread-63] INFO  ch.cyberduck.transcript.response - 227 Entering Passive Mode (62,210,18,29,249,231)

I suppose the server is misconfigured. We should probably change the default¹ to verify the address returned for the data connection.

Footnotes

1. https://github.com/iterate-ch/cyberduck/blob/7b6fdd3271e2752abe1dcc39fc61d03ffa43c10d/defaults/src/main/resources/default.properties#L251 ↩