Microsoft KB Archive/287617

= XCCC: Firewall or Proxy Software Prevents NetMeeting from Starting =

Article ID: 287617

Article Last Modified on 1/31/2007

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APPLIES TO


 * Microsoft NetMeeting 3.0
 * Microsoft NetMeeting 2.11
 * Microsoft NetMeeting 2.1 Standard Edition
 * Microsoft NetMeeting 2.0 Standard Edition
 * Microsoft NetMeeting 3.0
 * Microsoft NetMeeting 3.0
 * Microsoft NetMeeting 2.11
 * Microsoft NetMeeting 2.1 Standard Edition
 * Microsoft NetMeeting 2.0 Standard Edition
 * Microsoft NetMeeting 3.01 Standard Edition
 * Microsoft NetMeeting 3.0
 * Microsoft NetMeeting 2.11
 * Microsoft NetMeeting 2.1 Standard Edition
 * Microsoft NetMeeting 2.0 Standard Edition
 * Microsoft NetMeeting 1.0 Standard Edition
 * Microsoft NetMeeting 3.01 Standard Edition
 * Microsoft NetMeeting 3.01 Standard Edition
 * Microsoft NetMeeting 3.01 Standard Edition
 * Microsoft NetMeeting 3.01 Standard Edition
 * Microsoft NetMeeting 3.01 Standard Edition

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This article was previously published under Q287617



SYMPTOMS
When you start Microsoft NetMeeting, you may receive the following error message:

NetMeeting Could Not Start. Please Restart Your Computer and Try Again.



CAUSE
This behavior occurs if you are using firewall or proxy software that is blocking the necessary ports that NetMeeting requires to run properly.



RESOLUTION
To enable NetMeeting data conferencing and to use the Program Sharing, Whiteboard, Chat, or File Transfer features, your firewall only needs to pass TCP connections through port 1503.

NetMeeting audio and video features require secondary TCP and UDP connections on dynamically assigned ports. Therefore, if you establish connections through firewalls that accept only primary TCP connections, you cannot use the NetMeeting audio or video features.

To provide audio and video through a firewall, configure the firewall to do the following:
 * Pass through primary TCP connections on ports 389, 522, 1503, 1720, and 1731.
 * Pass through secondary TCP and UDP connections on dynamically assigned ports (1024-65535).



WORKAROUND
To work around this behavior, disable or remove the firewall or proxy software.



MORE INFORMATION
The following third-party software may impact the functionality of Microsoft NetMeeting:
 * BlackICE Defender by Network ICE
 * ZoneAlarm by Zone Labs
 * Wingate by Deerfield.com
 * Sybergen Secure Desktop by Sygate

The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.

Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.

Keywords: kbnofix kbprb KB287617

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