problem with the FTPS connection, Error code 421

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ad20201216
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problem with the FTPS connection, Error code 421

#1 Post by ad20201216 » 2021-01-27 01:44

I am having a problem with the FTPS connection. Details are as follows:
server OS:Windows Server 2012 R2
server :Filezilla 0.9.43 beta
client OS:Windows 7
I use apache commons net 3.7.2 as base lib,and extend FTPSclient,my code as follow:
Image
and i get client error
Image
filezilla server's error log:
Image
error id is 004056
This error occur randomly, and may occur after a few connections or dozens of connections.

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boco
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Re: problem with the FTPS connection, Error code 421

#2 Post by boco » 2021-01-27 01:52

You are using an unsupported version of FileZilla Server. Please update to 0.9.60.2 as it's the only one supported.
### BEGIN SIGNATURE BLOCK ###
No support requests per PM! You will NOT get any reply!!!
FTP connection problems? Do yourself a favor and read Network Configuration.
FileZilla connection test: https://filezilla-project.org/conntest.php
### END SIGNATURE BLOCK ###

ad20201216
500 Command not understood
Posts: 2
Joined: 2021-01-26 11:08
First name: Jiang
Last name: YuanChen

Re: problem with the FTPS connection, Error code 421

#3 Post by ad20201216 » 2021-01-28 01:54

thanks for u reply,but I can't upgrade the version of filezilla in production environment.

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botg
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Re: problem with the FTPS connection, Error code 421

#4 Post by botg » 2021-01-28 10:32

Rant: I'm seriously considering to add a killswitch to all my products so that they _HAVE_ to be updated regularly...

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boco
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Re: problem with the FTPS connection, Error code 421

#5 Post by boco » 2021-01-29 03:23

ad20201216 wrote:
2021-01-28 01:54
thanks for u reply,but I can't upgrade the version of filezilla in production environment.
Your "production environment" is in grave danger. That ancient version contains multiple severe security vulnerabilities actively being exploited in the wild. Additionally, no one here really knows anymore how that version worked and behaved, as we moved on.
For your own good, you really need to come up with a concept for doing proper server maintenance. Most simply, run a backup server to keep production up while upgrading. Or, prepare a fully updated FTP server with identical configuration, test it on a spare machine, then, do an in-place switch. Easy to do with FileZilla Server and keeps downtime short.
botg wrote:Rant: I'm seriously considering to add a killswitch to all my products so that they _HAVE_ to be updated regularly...
Good idea. You can't keep users from running old versions, as it's Open Source Software, after all. But those forks will not get any support here, as the GPL license states.
### BEGIN SIGNATURE BLOCK ###
No support requests per PM! You will NOT get any reply!!!
FTP connection problems? Do yourself a favor and read Network Configuration.
FileZilla connection test: https://filezilla-project.org/conntest.php
### END SIGNATURE BLOCK ###

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