Troubleshooting SFTP

SFTP connection issues are typically caused by firewalls or incorrect settings in SFTP software. The steps below help you resolve these issues.

When a connection that previously worked stops working, the change that caused the problem is almost always on the client side. Work through the items below before contacting us for further help. These are the same steps we walk through together on a Zoom call.

• Local network / firewall issues
• Connection settings in your SFTP app
• SFTP Configuration on Files.com that may be relevant
• Invalid authentication, username, or password
• Key Mismatch Login Failures
• Connection Fails When Using Fallback Cipher
• Failed SSH Key Exchange or Bad server public DH value error when using Ipswitch WS_FTP or MoveIt
• Partially uploaded files

Asynchronous Considerations

The Files.com platform performs some operations asynchronously and these operations will run in the background in parallel.

SFTP clients are unaware of asynchronous background operations.

For example, using the SFTP rename command to move a file from one Files.com storage region to another, or from one Remote Server Mount to another, will asynchronously create a background process to move the file. Control is immediately returned to the SFTP client even though the move is still occurring in the background.

If you are programmatically interacting with SFTP, such as from a script or iPaaS process, then the next commands will execute while the move operation is still in progress. If your script, or process, immediately tries to access the moved file then it will fail because the move operation hasn't completed yet.

A reliable integration with Files.com accounts for these asynchronous background operations. Build verification steps into your scripts and processes that confirm a moved, renamed, or copied file is available at the destination before taking any further action on it.