Connection Settings In Your FTP App

The following connection settings are the next most common issues related to FTP. Please double check all of the following items.

Hostname

The hostname should be set to [your_subdomain].files.com or the custom domain for your site, if applicable. Connecting by specifying an IP address may sometimes work, and we do have customers doing this for specific reasons, but it is not officially supported.

Encryption

If supported in your client, encryption should be enabled. Some clients show this as a protocol setting, offering FTPS or FTPeS (with the "S" meaning "secure"). This means data will be encrypted in transit. If you are unable to use encryption, in your FTP client, insecure FTP without encryption must be enabled in your Files.com account.

Port

The port setting is a great way to work around corporate firewalls. The default FTP port of 21 is blocked or interfered with by many corporate firewalls. You can test port 3021 as an alternate port if you suspect possible firewall issues. Some FTP clients use "implicit security mode", which runs on port 990. In this case, we also support port 3990 as an alternative. In many cases, simply using the alternate port will get your corporate firewall to let the connection through.

Active vs Passive Mode

Many FTP clients offer a choice of Active Mode versus Passive Mode. Files.com supports both, but your corporate firewall might block one or the other. We recommend testing both options in conjunction with testing the alternate ports in the above step.

Timeout

If supported in your client, increase the connection timeout value to 60 seconds.

Retry Logic

If supported in your client, have your client attempt three connection retries at 10 second intervals. This allows failed connections contacting one server to retry the connection via a different server. Our hostnames always resolve to multiple physical server hosts in different datacenter locations. Ensure that your FTP client tries multiple IPs when available.

Keepalives

Files.com will time out FTP sessions that have been idle for 60 seconds. This is to prevent unused sessions from being left open and using server resources. Such idle timeouts are normal, and most FTP clients handle them without issue, but there are some clients that may not handle these timeouts gracefully. To prevent these idle timeouts, many clients offer a "keepalive" setting. Many FTP clients will complete transfers in progress and then will connect again upon the user issuing another command. If your client aborts a transfer or errors out due to the idle timeout message, you can implement keepalives (either null packets or dummy commands) every 30 seconds to maintain the FTP connection and avoid the timeout messages.