There can be several cases in what you might want to block access to MSN Messenger. For example, in corporate or school environment or when you have children you might want to disallow them to chat. In this article we will describe how to block access to the .NET Messenger service through your firewall.
MSN Messenger can communicate with the .NET Messenger service using eiter port 1863 for direct TCP connections or using HTTP port 80. To block access to .Net Messenger service:
Aside of the normal MSN Messenger client there are also several webclients available that you might want to block from HTTP access: