If you are uploading/downloading too many files at once through FTP, you risk the chance of being blocked by the shared server firewall for too many concurrent connections. To resolve this issue, follow these simple steps to limit the number of connections FileZilla uses.
- Start Filezilla FTP
- Click Edit and then Settings
- Select Transfers
- Under "Concurrent transfers" set Maximum simultaneous transfers value to 1 and click on OK to save the changes.
Changing max number of concurrent FTP connections on a per-site basis
- Start Filezilla FTP client
- Click File, and then Site Manager
- Select your Site from the left-hand menu
- click the Transfer settings tab
- Check the box for “Limit number of simultaneous connections” and set Maximum number of connections to 1.
- Click OK to save the changes.