FileZilla Forums

Dear botg,

The way you handled this is just beyond comprehension. I'm guessing customer support is not your forte.

No other software was updated except FileZilla. After said update FileZilla no longer works. People, myself included are curious as to why. A question is posted to the forum. Then you treat everyone asking about it like crap. Your are arrogant. Even if you think people are ignorant still respond with respect. Maybe they have not heard of netsh or netstat or even command line. I think FileZilla should have this ability put into it, why ask the customer. Seriously FileZilla is asking users to create troubleshooting logs, what kind of software is this. Take it one step further and have it emailed to you, don't even ask them to do that. You assume they don't do this because "users were refusing" when maybe they don't know how.

You blame Kaspersky, CE, Windows Firewall, Windows Defender, and any other pieces of software. You call them spyware. I repeat myself nothing has changed except an update to FileZilla. One day it works next day it does not, yet it is everyone else's problem.

Rhetorical questions no need for answers, how many customers asked for this super secure update? How many times does an attack happen that this update prevents? How vulnerable is a customer without this update?

People have come to the forum with an upbeat attitude trying to make FileZilla better. Trying to make all things work together. But with your attitude and your response you turn the jubilant environment into an argument and disdain.

Good luck, after many years of using FileZilla I'm now moving on. In addition to not using it I will also let my customers know not to use it as well. I would hate for them to come here for support and get a response from you.

The solution to the problem WinSCP or CyberDuck.
Why not just move to IPv6 ONLY and then blame FileZilla not working on everyone else because they are using IPv4?

Perhaps a simple analogy will help you understand the problem more clearly.


Imagine there is a tunnel. The sign in front says it has a clearance of 3m and since the tunnel got built, only compact cars have driven through the tunnel.

Now a heavy truck comes along, 2.8m in height, and promptly gets stuck in the tunnel. It turns out the tunnel only actually has a clearance of 2 meters.

Clearly it's either the sign or the tunnel that's at fault. Yet you would you say that it's the truck that's at fault in this situation.

Had the tunnel a clearance of at least 3 meters as the sign said, the truck would not have become stuck. Likewise, if the sign would have said 2m to match the tunnel, the truck wouldn't have attempted to drive through the tunnel and wouldn't have become stuck either.


Your firewall vendor built the tunnel and put up the sign. It is only them that can make the sign match the tunnel.

To summarize the facts:

FileZilla establishes the control connection to a server with a particular destination IP, let's call this address B.

This connection is established from source IP address A, the system automatically assigns the best matching A to the connection.

At this point, we know that it is in fact possible to connect from A to B.

To transfer a file or directory listing, a secondary data connection has to be opened. FileZilla binds the source address to A and connects to B.

This works fine except when using Kaspersky where we suddenly get ENETUNREACH, "Network unreachable". Something suddenly tells us B cannot be reached from A while we at the same time already have a working connection from A to B.

In other words, FileZilla does something that is known to work (the working control connection is living proof) and Kaspersky does something to break it.

I read you tunnel analogy before.

More like, truck drives thru tunnel day one, day two truck is rebuilt, day three truck unable to drive thru tunnel. Now it is the tunnels fault. The tunnel did not change the truck did. No need for a sign or compact cars.

What about CE, Windows Firewall, or Windows Defender? Customer with Kaspersky was not the only one.

Control connection: Source IP bound to A and connecting to B
Data connection: Source IP bound to A and connecting to B

It's the very same truck used in both cases.

stealthtech wrote:More like, truck drives thru tunnel day one, day two truck is rebuilt, day three truck unable to drive thru tunnel. Now it is the tunnels fault. The tunnel did not change the truck did. No need for a sign or compact cars.

You are forgetting about the sign in front of the tunnel. The sign says the rebuilt truck fits through the tunnel.

stealthtech wrote:What about CE, Windows Firewall, or Windows Defender? Customer with Kaspersky was not the only one.

This has nothing to do with Windows Defender of Windows firewall. As for CovalentEyes, that firewall needs to be updated as well.

boco wrote:Control connection: Source IP bound to A and connecting to B
Data connection: Source IP bound to A and connecting to B

In the first case it is implicitly bound by the operating system during the connect().

In the second case it is explicitly bound by FileZilla prior to the connect().

Same problem here

I did a full uninstall
<removed advertisement> (use at own risk )

then installed 3.10.3

And it works again. (or use winscp)

What does your firewall vendor say when they will have fixed this bug in the firewall?

So just to be clear the only way to avoid this problem is to downgrade to 3.10 correct?
Can someone provide a link to 3.10 version?

Thanks in advance for your time.

You can always contact your firewall vendor to have your firewall fixed. Why is it so hard to address the root cause?

You are no doubt right, but that doesn't actually help the situation. I work in the software industry and we deal with third party vendors in similar circumstances.
You have put the burden on the users to fix a problem revealed by an upgrade to your software. Even if that problem stems from a fault in the third party the users will inherently blame you for it causing great angst as we have all seen. I would have put in a config option that allows the users to do it the 'wrong way' and moved on. You can hold the high ground because it is free, but in a pay model you have had no choice. Anyway I found a 3.10 install so I am happy. Thank you for your efforts and time.

If FileZilla offered an option to 'continue the wrong way', nothing would change ever. The Firewall or Antivirus vendors would just instruct users to enable that switch instead of fixing their broken stuff. Sad but true.

Furthermore, continuing the wrong way would also weaken protection against FTP data connection stealing. The fact of using a firewall would decrease security!

I have the same problem with ftp://supportftp.veeam.com/, FTP from DELL and many others

No problem with 3.10.3
Instant problem with 3.12.02

While FileZilla might do everything right it still is a tool to connect to FTP servers. If it cannot reach major companies anymore FileZilla is simply unusable. So the developers have to decide if the provide some fallback (even a checkbox would do) so their tool works like intended (connect to as many FTP servers as possible) or make it a super secure obscurity, which behaves super correct while being unable to do what it was designed for. I am not talking about some unimportant FTP servers out there. Veeam, Dell, VMWare and others will simply not change their servers if I tell them, that FileZilla does everything right.

I would appreciate an honest answer since we include FileZilla in every Windows image of our institute and if it's staying like this we have to exchange it with something more reliable and user friendly. Would be sad, since we all love FileZilla.

badger42 wrote:You have put the burden on the users to fix a problem revealed by an upgrade to your software.

+1

badger42 wrote:Even if that problem stems from a fault in the third party the users will inherently blame you for it causing great angst as we have all seen.

That's exactly what happened here. I cannot explain dozens of users that they simply have to write emails to all kind of major companies that their FTP server or firewall does something wrong. Which was no problem with the same ftp client for years until one month ago. They will simply be told to use another client (like I was told be veeam and Dell) and there is no leverage to do otherwise. So FileZilla might win the argument, but will simply not be used anymore. That's not a Win-Win situation.

Today I had to inform all users that they have to downgrade to 3.10.3. That's the only solution possible except of looking for a new client.