You may receive an "Unable to connect to" error message when you try to debug a process through a firewall on a remote computer (816763)

The information in this article applies to:

Microsoft Visual Studio, Enterprise Edition 6.0
Microsoft Visual Studio .NET (2002), Academic Edition
Microsoft Visual Studio .NET (2002), Enterprise Architect Edition
Microsoft Visual Studio .NET (2002), Enterprise Developer Edition
Microsoft Visual Studio .NET (2002), Professional Edition
Microsoft Visual Studio .NET (2003), Academic Edition
Microsoft Visual Studio .NET (2003), Enterprise Architect Edition
Microsoft Visual Studio .NET (2003), Enterprise Developer Edition
Microsoft Visual Studio .NET (2003), Professional Edition

SYMPTOMS

When you try to debug a process through the firewall on a remote computer, you may receive one of the following error messages:

Error message 1:
Unable to connect to xxx.xxx.xxx.xxx. The remote machine is not responding.
Note The placeholder xxx.xxx.xxx.xxx is a placeholder for the Internet Protocol (IP) address of the remote computer where you are trying to debug the process.
Error message 2:
Unable to connect to Computer Name. MSVCMON is not running on the remote machine.
Note The placeholder Computer Name is a placeholder for the name of the remote computer where you are trying to debug the process.

CAUSE

The Remote Debug Monitor (MSVCMON) process communicates with a fixed-port number from 2064 through 2079. If the firewall blocks the ports from 2064 through 2079, the MSVCMON process fails.

RESOLUTION

To resolve this problem, do not block the ports on the firewall from 2064 through 2079. If the ports from 2064 through 2079 are blocked, a system administrator can unblock the ports.

STATUS

This behavior is by design.

MORE INFORMATION

You can use the "telnet" command-line utility to verify that a port is blocked. At the command prompt, type the following command:

telnet xxx.xxx.xxx.xxx 2064

Note The placeholder xxx.xxx.xxx.xxx is a placeholder for the IP address of the remote computer.

If port 2064 is not blocked, you receive the following message:

connected to the remote system

If port 2064 is blocked, you receive the following error message:

Connect failed

REFERENCES

For additional information, visit the following Microsoft Developer Network (MSDN) Web sites:

Setting up remote debugging

http://msdn.microsoft.com/library/en-us/vsdebug/html/vctskInstallingRemoteDebugMonitor.asp

How to enable remote debugging on Windows XP Service Pack 2

http://msdn.microsoft.com/library/en-us/dnwxp/html/xpsp2remotedebug.asp

Modification Type:	Minor	Last Reviewed:	8/15/2005
Keywords:	kbnetwork kbIP kbtshoot kberrmsg kbprb kbFirewall KB816763 kbAudDeveloper