If your FTP access is being temporarily blocked when using FileZilla, it is usually because your computer, internet connection, router, or FileZilla settings are creating too many FTP connections to the server at once.
This can happen even if FileZilla appears to be set to only use a small number of connections. FTP can open separate connections for directory listings, uploads, downloads, retries, and passive data transfers.
Why This Happens
FTP is different from normal web browsing. It may use:
- A control connection
- Separate data connections for uploads and downloads
- Additional connections for directory listings
- Retry connections if transfers fail
If FileZilla repeatedly reconnects, retries failed transfers, or transfers many small files, your IP address may appear to the server as having hundreds of open or recently-opened connections.
When this happens, the server firewall may temporarily block the IP address to protect the server from excessive connection usage.
Recommended FileZilla Settings
1. Limit FileZilla to One Connection
Open FileZilla and go to:
File → Site Manager → Select your site → Transfer Settings
Enable:
- Limit number of simultaneous connections
Set the value to:
1
2. Set Global Transfer Limits
Go to:
Edit → Settings → Transfers
Set the following:
- Maximum simultaneous transfers: 1
- Maximum simultaneous downloads: 1
- Maximum simultaneous uploads: 1
3. Increase the Timeout Value
Go to:
Edit → Settings → Connection
Set:
Timeout in seconds: 60
If you continue having problems, try:
Timeout in seconds: 120
4. Reduce Transfer Retries
Go to:
Edit → Settings → Transfers
Set:
- Retry attempts: 1
- Delay between failed login attempts: 30 seconds
This helps prevent FileZilla from creating repeated failed connection attempts.
5. Use Passive FTP Mode
Go to:
Edit → Settings → FTP → Passive Mode
Ensure Passive Mode is selected.
Passive FTP is normally the best option for users behind home routers, office routers, or ISP connections.
6. Disable FTP Keep-Alive
Go to:
Edit → Settings → FTP
If enabled, untick:
- Send FTP keep-alive commands
Recommended Test
After changing the settings above:
- Close FileZilla completely.
- Restart your modem/router.
- Reopen FileZilla.
- Connect to FTP again.
- Upload one single file as a test.
If the issue only happens when uploading many small files or syncing a full website, the issue is likely caused by FTP connection churn or repeated transfer retries.
Router or Internet Connection Issues
Some routers and internet providers may interfere with FTP or FTPS connections. This is especially common where a router has FTP inspection, FTP ALG, or advanced firewall features enabled.
If your router has an option called FTP ALG, try disabling it.
You may also wish to test from another internet connection, such as a mobile hotspot, to confirm whether the issue is related to your local router or ISP connection.
Best Solution: Use SFTP Instead of FTP
Where available, we recommend using SFTP instead of standard FTP or FTPS.
In FileZilla, create or edit your site and set:
- Protocol: SFTP - SSH File Transfer Protocol
SFTP is more reliable because it normally uses one secure connection instead of multiple FTP data connections.
This reduces the chance of firewall blocks and is generally more stable for website uploads.
Summary
If your IP address is being blocked while using FileZilla, please check the following:
- Set FileZilla to use only 1 simultaneous connection
- Set global upload/download limits to 1
- Increase timeout values
- Reduce retry attempts
- Use Passive FTP mode
- Restart your modem/router
- Try SFTP instead of FTP where possible
If the issue continues after applying these settings, please contact our support team and include your current public IP address, the FTP username, and the approximate time the block occurred.
