Error Case: Max FTP Connections

Main issues behind Max ftp connections error

You might encounter a problem when transferring files through an FTP client, where the number of connections to the server is reached. Our servers limit you to 4 simultaneous connections. Should you encounter these errors regularly, there are solutions!

Prerequisites

  • Access to cPanel or

  • Access to Funio Hub

Task completion: 10 minutes

Expertise: Intermediate

Diagnostic: Errors

Here are the most common errors you might encounter, depending on your FTP Client. 

  • 530 Sorry, the maximum number of connections (4) for your host are already connected.
    Error: Critical error
    Error: Could not connect to the server

  • Response: 421 Too many connections (4) from this IP
    Error: Could not connect to the server
    Status: Delaying connection due to previously failed connection attempt...

Change Transfer Settings

There are multiple settings you can fiddle around with, in your FTP Client. The best way to avoid encountering the "max connection" error, is to limit your FTP client to a specific number of connections. Here is an example of where to find this option with FileZilla, on Mac OS X.

  1. To go to the menu bar on top, and select FileZilla > Preferences

  2. In the settings window, locate and select Transfers

  3. Change the Maximum simultaneous transfers setting to 4

  4. Click OK.

The second setting we recommend you look into is the FTP Transfer Mode, which can be either Passive or Active. To learn the difference, you must first know that to have a successful FTP transfer, there are two channels being used for the transfer, one for command the other for data.

  • Active: FTP client determines command channel. FTP server determines data channel.

  • Passive: FTP client determines both channels (data port is random).

We recommend using Passive mode because it avoids being blocked by firewalls and is a more reliable transfer method. You can change this setting in your FTP client. Here is an example using FileZilla on Mac OS X.

  1. To go to the menu bar on top, and select FileZilla > Preferences

  2. In the settings window, locate and select FTP

  3. Select Passive

  4. Click OK

Verify Your Internet Connection

This may sound a bit ridiculous, but oftentimes the problem stems from intermittent connectivity. This may be caused by a faulty router or bad internet sync. Regardless of the source of a bad internet connection, the result is often that while there is a transfer, whether it is successful or not, the laggy internet connection can prevent the FTP client and the FTP server from completing their communication. Therefore, an FTP connection could remain active because the connection closing was not done properly, so the server keeps an active connection in its list of connections. See the next section (View & Terminate FTP Sessions) for more information.

View & Terminate FTP Sessions

When you encounter a "Max connection" error, and it becomes stubborn, you may want to start by closing the FTP Client, and then look at the FTP Connection Sessions on the server. Here is how to get there:

  1. Log into your cPanel Control Panel

  2. Locate the Files > FTP Accounts > FTP Session Control section

  3. If you have closed your FTP Client, and that you are certain no one is using the FTP protocol, there should be no active sessions. If your FTP Client is still opened and you are certain there are no transfers happening (uploads or downloads), you should only see IDLE connections, which is normal.

  4. If there are UL or DL (UpLoad / DownLoad) connections that seem "stuck" to you, disconnect them. You can also disconnect IDLE connections to be sure, but you will have to reconnect to the server with your FTP Client afterward.

  5. Make sure your FTP client has no activity and refresh this page. If new connections appear, this means someone is connecting to the server through FTP. The user and Logged In From should help you determine who is using it and from where. If you suspect foul play, go and reset your FTP password from the FTP Accounts section

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