7503: Using telnet to Test Open Ports

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With the telnet command you can test if a port is open.


You can check if a port is open in your network by issuing the telnet command. If it is open, you will see a blank screen after issuing the command:

telnet [domainname or ip] [port]


  • [domainname or ip] is the domain name or IP address of the server to which you are trying to connect
  • [port] is the port number where the server is listening

If the port is open, you will see a blank screen. This will mean that connection is successful.

In Windows Vista and Windows 7 you may need to enable telnet first:

  1. Go to Start -> Control Panel -> Programs.
  2. Under Programs and features, click Turn Windows features on or off.
  3. Mark both Telnet Client and Telnet Server.
  4. Click OK.


telnet rpc.acronis.com 443

More information

If backup to Acronis Cloud is failing, use Acronis Cloud Connection Verification Tool to check the connection.