Generally, you would need to add a filter on your router (access-list) so it does not allow TCP connections to the messenger service by blocking the TCP port listed and also port 80. Keep in mind that MSN may change the Ip address from time to time and this will require you to add/change the access-list so your internal users are unable to access the updated servers.
If you had a proxy server this will be the preferred way of blocking this type of service.
Troubleshooting a failed ISE Upgrade Readiness Tool Assessment
About the Author
Richard Atkin is an Engineer at a Cisco Partner in the UK, specialising in ISE, WiFi & Prime... I'm also currently learning about APIs, Webhooks, AWS, (etc et...
Security Product and architecture introduction-NGFW portflio(8/6)
Troubleshooting a failed ISE Upgrade Readiness Tool AssessmentAbout the AuthorSituationResolution
The following document will enable you to add a Mobility Express Controller to your ISE instance in dCloud.
You will need a dCloud ERK (Endpoi...
how do I enable the support for TFO (RFC 7413) in Cisco Adaptive Security Appliance Software Version 9.2 ?
It seems not to work out of the box, i.e. normal connection establishment (handshake without application data bytes) work...