This will guide on how to verify if the FTPS certificate is configured correctly in Serv-U. Some FTP clients like FileZilla has a prompt that the certificate is unknown:
The server's certificate is unknown. Please carefully examine the certificate to make sure the server can be trusted.
Certificate in chain: 0 and 1
All Serv-U MFT versions
This behavior is default by design from Filezilla client and there is no way to skip it. (Reference: FileZilla: SSL Certificate Installation Instructions and check filezilla forums). If you do not want to see such prompts, then try with some other clients such as WinSCP, etc..
To check if the FTPS certificate is loaded properly on Serv-U, please try this command for FTPS implicit:
Syntax: openssl s_client -showcerts -connect [FTP SITE]:990
You may test using our demo site:
openssl s_client -showcerts -connect ftp-server.demo.solarwinds.com:990
Disclaimer: Please note, any content posted herein is provided as a suggestion or recommendation to you for your internal use. This is not part of the SolarWinds software or documentation that you purchased from SolarWinds, and the information set forth herein may come from third parties. Your organization should internally review and assess to what extent, if any, such custom scripts or recommendations will be incorporated into your environment. You elect to use third party content at your own risk, and you will be solely responsible for the incorporation of the same, if any.