A couple days ago I had to solve a strange issue regarding one of our machines seemingly unable to connect to a public FTP server: the PC in question was trying to connect using FileZilla, the well-known open-source FTP Client by FileZila Project available here. The given error was the following:
ENETUNREACH – Network unreachable
Since the FTP server was perfectly reachable by other machines – also using FileZilla themselves as well – I started to look closer on the client. To cut it short, it turned out that the problem was related to the Kaspersky Antivirus TCP filter, which incorrectly behave with a FileZilla estabilished connection breaking it out.
Luckily enough this is a well-known problem on the FileZilla Project website, which even features a dedicated page explaining how to properly fix it. For your convenience, these are the required steps:
- Double click on the Kasperskysystray icon (the red “K” near the system clock).
- From the newly-opened windows, click on the “Settings” tab, then navigate to the “Anti-Virus protection” category.
- In the new panel that will show, locate and click on “Firewall“.
- To the right part of the new window, click to the “Application network rules…” button.
- Click on the “Application” column to filter the items.
- Browse the item list until you find “FILEZILLA PROJECT“: expand it by clicking to the “+” icon.
- Click on the “filezilla.exe” entry: an info panel will appear.
- Click on “Additional…” to show a new window, called “Application control rules“.
- Click on the “Exclusions” tab and check the following options:
- “Do not inherit restrictions of the parent process“
- “Do not scan network traffic“
That should do it. If this brief guide isn’t enough, take a look to this great post by tDailyLama on the FileZilla official forum which basically explains it all and also has some pictures on the Kaspersky interface.