What FTP Mode does Vault use?
Our service is strictly PASSIVE mode Explicit FTPS (a.k.a FTPES).
Any references to ACTIVE mode, Implicit FTPS, port 990, plain old FTP or SFTP are indications of functionality that Veeva does not support. The settings related to them should be changed. SFTP is a different protocol from FTP. The other terms are related to ACTIVE mode and Implicit FTPS which are not able to connect to Veeva's FTP server.
Vault Help Documentation: Accessing Your Vault's File Staging Server