Unable to connect to a Plesk server via FTP: Server sent passive reply with unroutable address. Using server address instead.

Symptoms

• In FileZilla, an FTP connection or a file upload fails with the following error message:

  Status: Connecting to 203.0.113.2:21...
  ...
  Server sent passive reply with unroutable address. Using server address instead.

• When establishing an FTP connection locally from the server, a private IP address is returned and connection fails with "No route to host":

  # ftp 203.0.113.2
  Connected to 203.0.113.2 (203.0.113.2). <--- the public IP
  220 ProFTPD 1.3.5d Server (ProFTPD) [203.0.113.2]
  Name (35.154.187.139:root): john_doe
  331 Password required for username
  Password:
  230 User username logged in
  Remote system type is UNIX.
  Using binary mode to transfer files.
  ftp> ls
  227 Entering Passive Mode (192,0,2,2,170,123). <--- the external IP
  ftp: connect: No route to host

Cause

A public IP address is not configured for a private IP address in Plesk at Tools & Settings > IP Addresses.

Resolution

1. Configure the passive FTP ports:

   • for Plesk on Linux

     How to configure the passive ports range for ProFTPd on a server behind a firewall

   • for Plesk on Windows Server

     How to configure a passive FTP port range on Windows Server

2. Log in to Plesk and associate a public IP address with a private IP address at Tools & Settings > IP Addresses.

   

   On a Linux server, to find a public IP, use the steps below:

   1. Connect to the Plesk server via SSH.

   2. Run the following command:

      # curl ifconfig.co