An error arose on port 21

[FillTech]

System Info:
1and1 Virtual Private Server -- Quad Core Opterton 2352, 2.11GHZ, 1GB RAM
Windows Server 2003
Standard Edition (x64)
Service Pack 2

Single network interface.

WingFTP Standard with one domain, listening only on FTP:21

I randomly receive an error in the Domain Log highlighted in red with white text:
[14] <date / time> An error arose on port 21(error code:995).Server try restart on port 21


I'm assuming error code 995 is the windows error code indicating an overlap of services.
IIS has been completely uninstalled from this machine.
I have tried disabling both Windows Firewall and Application Layer Gateway Services
Neither has helped.

Other than an FTP client (which is not running), Filezilla, and remote-backup software (which only calls out and doesn't use port 20 or 21 at all) -- Nothing else has been installed on this server.

I downloaded and ran Malware Bytes - Anti Malware just for sanity, and it also came up clean.

Right now, this is basically unusable for production, as it has to be manually restarted at least once an hour.

I'm out of ideas at this point. Please help.

[FTP]

Hi,

It is very strange problem! we can't simulate it in our machines.
We have found some similar problem solutions by google, here is one of those:

To fix this problem, you can make 2 different registry changes on the your server.
1.Increase the dynamic port range. As stated above, the default is 5000 but this can be raised up to 65534.
Using Regedit, navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\MaxUserPort (if this key does not exist, create it as DWORD value)
Set the value to 65534, or a value of your choice

2.Reduce the amount of time that the connection is in a TIME_WAIT state.
Using Regedit, navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\TCPTimedWaitDelay (if this key does not exist, create it as DWORD value)
Set the value to 30

Good Luck!

[FillTech]

The problem is happening on both servers. I thought the 2nd was stable, until I redirected the DNS to it.

I will try this fix, and let you know.

The MaxUserPort was already set at 60000, but the TCPTimedWaitDelay key did not exist previously.

Thanks

[FillTech]

Server ran 1 hour and 47 minutes before the error popped up again and killed the domain.

Highest Num Sessions was only 14 during this period, total sessions around 750.


This doesn't seem like an extraordinarily heavy load to me. I can try increasing the MaxUserPort from 60000 to 65000, but I don't know if that will make much difference with it already at 60k.

[FillTech]

No Dice.

Both servers experience the same issue. Registry entries did not fix it. (yes, I did reboot after making the regedits) I can't keep resetting services every hour or two every day and night.

Can the domain restart be automated as a workaround? Would you like to take a look at the servers remotely?

Let me know.... Thx.

[FTP]

Hi,FillTech

We have released Wing FTP Server 3.1.0 just now, please update your software to the current version.

[FillTech]

Ver 3.0 Uninstalled, Ver 3.1.0 Installed.

Error persists.

[FTP]

Thanks for your post. We are doing our best to fix this problem.

[Marcel]

Hi,

We also get the same errors on all our active ports (21 and 443).
But at the same time this one;
[02] Wed, 11 Nov 2009 10:02:37 Only one usage of each socket address (protocol/network address/port) is normally permitted
[02] Wed, 11 Nov 2009 10:04:54 Only one usage of each socket address (protocol/network address/port) is normally permitted
[02] Wed, 11 Nov 2009 10:11:52 Only one usage of each socket address (protocol/network address/port) is normally permitted

Configuration;
Win2003 Server STD UK SP2
Wing FTP Server Corporate V3.1.2 with 2 domains and a total of 19 users.
The registry is already patched but this did not solve the problem.

This version is not stable. Is is possible to reïnstall a stable (older) version?

Regards,
Marcel

[FTP]

You can re-install the old version, but are you sure that old version is stable and has no problem?