Topic "TLS/SSL FTP explicit file transfer, control connection timeout"

Author Message
[View user's profile]

Joined: 2015-11-15
Posts: 1
Hi all,
My provider firewall's TCP session timeout is ~5 minutes. Local and the remote side behind NAT+firewall. I use TLS/SSL FTP explicit connection. Connection settings: Passive mode, Executing dummy protocol commands, seconds between keepalives: 30 seconds.

If the file transfer takes longer time than the session timeout, after uploading a file is completed, I get "Timeout detected. (control connection)" message (but only when the transfer takes longer than time of the session timeout per file).

I think, while uploading files, the control connection TCP session is disconnected, beceause keepalives not sent.

It is possible while uploading files send keepalives to prevent control connection TCP session disconnected? (Putty 0.66 connections disconnect here too, without set seconds between keepalives)

Thank you!
ftp_tls_ssl_expl_control_no_timeout.log (43.36 KB) Private file

Description: Transfer time per file shorter than session timeout.

ftp_tls_ssl_expl_control_timeout.log (89.34 KB) Private file

Description: Transfer time per file longer than session timeout.

[View user's profile]
Site Admin
Joined: 2002-12-10
Posts: 26890
Location: Prague, Czechia
No, you cannot send keepalives on FTP control connection while the transfer is ongoing.


Same problem with my wireless provider, with almost same configuration, but for me the TCP disconnect time is only 2 minutes. The service provider does not want change the session timeout value.

Feature request: After the file transfer finished, if the control connection disconnect is occurs, try first auto reconnect without error window, and without wait until reconnection timeout expires and go to the next file, or close the file transfer process. The error window show up, if second reconnection fails too.



I read You bug-report in Far Manager Mantis. Please, go to NetBox panel, Your session, Connection, and set Time-aut > 300s and check box "Executing dummy protocol commands" for correct current FTP settings. Is local server settings problem.

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