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Unable to connect to Serv-U Server using Filezilla

This article provides possible reasons why users could not connect to Serv-U and get the following error Error: The data connection could not be established: ENCOUNTERED - Connection refused by server. Authentication failed Critical error: Could not connect to server

First published date

10/4/2019 10:16 AM

Last published date

11/18/2020 6:01 PM

Overview

The user may encounter issues connecting to the Serv-U server to transfer files. Usually, you would get the following errors
  
The connection is being refused by the server.
Error: The data connection could not be established: ENCOUNTERED - Connection refused by server.

Authentication failed
Critical error: Could not connect to server

If the user is using LDAP authentication, you can check the Serv-U logs, if it's really connecting using the correct login format such as UPN or sAMAccountName and if there is a configured domain suffix in the LDAP authentication settings. You can validate it from the Serv-U logs.

Product section

Serv-U Managed File Transfer & Serv-U FTP Server

Cause

  • Invalid user credentials
  • Connection issues to LDAP server

Resolution

  • Make sure user credentials are correct
  • Restart Serv-U service to re-initiate LDAP connection