How to remotely verify if a router's ports are open

Article:TECH107907  |  Created: 2001-01-19  |  Updated: 2010-08-23  |  Article URL
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Technical Solution



You need to use pcAnywhere to connect over the Internet to a host that is behind a router. You need to check to see if the router's ports are open.



Use the Telnet command to verify that a router's ports are open:

  1. Click Start > Run
  2. In the run dialog box, type the following and press Enter
    • cmd
  3. At the command prompt, type the following command and press Enter
    • telnet
  4. Type the following and press Enter
    • open 5631
      where X's represent the IP address of the router

Depending on what you see, choose one of the following:

Receive a repeating "Please press <Enter>..."   or "Press any key to continue"
This shows that a program is answering on the port 5631 if you receive this response and are still unable to connect to a host or access server look for other applications that are utilizing port 5631.

"Could not open connection" or a blank screen with a blinking cursor:
One of the following is true:
The ports are closed.
You are using the wrong router IP.
The host is not waiting for a connection.
You are connecting through a firewall that is blocking the pcAnywhere ports.

"Connection to host lost"
The ports are open but the host is refusing the connection for some other reason.
Check for entries in the TCP/IP options that limit connections to specific addresses. Follow the steps below to check the TCP/IP options:

  1. Start pcAnywhere
  2. Click Edit > Preferences Or Tools>Options
  3. Go to the Host Communications tab.
  4. Ensure that there are no addresses entered in the "Limit connections to the following names or IP addresses" field. If there are, either delete them or add the address or name of the remote computer that you are trying to connect to.

Related documents:

Cannot connect to a pcAnywhere host through a router
Windows XP Internet Connection Firewall prevents pcAnywhere TCP/IP connection


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