FTP files get corrupted

Comodo Internet Security - CIS Firewall Help - CIS
#1

Hello

I have this anoying issue that when I download a file with any ftp client, that is larger than about 300 mb, the file gets corrupt. The only time it does not do that is if I turn off the Comodo firewall.

In my filezilla log I do see

22:40:19	Status:	Starting download of /mike/TinyXP-Rev09.iso
22:40:22	Status:	ftpcontrolsocket.cpp(1820): Waiting for replies to skip before sending next command...   caller=0p26828e8
22:40:42	Error:	Connection timed out

I have added filezilla.exe to my trusted program, what else do I need to let through to Filezilla inorder for this to work? Thanks for any help :slight_smile:

#2

Try using the FTP client policy for Filezilla. Does that help?

When it doesn’t help try temporarily disabling “Block fragmented IP datagrams” under Firewall → Advanced → Attack Detection Settings → Miscellaneous.

#3

Thank you for the reply. I already had Filezilla set to the FTP Client policy :slight_smile: I just now tried the “Block Fragmented IP Datagrams” however I still had a corrupt file.

Thanks for your support

#4

Any Ideas? I turned on Packet Checksum verification. But that didn’t help either :frowning:

#5

I just downloaded a 599mb file and it worked fine, but then I tryed my 717 MB and 8 GB files it did not work. GRRR All I know is when I turn off the comodo firewall the file downloads perfectly.
:cry:

#6

When the error happens do you see things logged in the Firewall logs? They can be found under Firewall → Common Tasks → View Firewall Alerts. Please post a screenshot of them.

#7

I went to Firewall Events and exported them. Hope that is what you mean. I see nothing wrong with the log.

Thanks!

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#8

I asked the other mods to take a look to see if collective effort brings more clarity.

#9

That would be great thanks!

#10

Hi Mike,

Please make certain that your FTP client (whatever flavour you prefer) is set to passive (PASV) mode. This is almost mandatory if you’re behind a firewall because of the way FTP host negotiate receive port settings.

Hope this helps,
Ewen :slight_smile:

#11

Here is more about FTP active v.s. passive

#12

Thank you. Bookmarked for reference.

#13

I will try, unfortunately you meet me right in between OS reinstall :slight_smile:

#14

Keep us posted. We will still be here when you are ready.