Exchange packets through Netbios Port UDP 137

 Issue:

We Spotted that, exchange server is trying to connect to MS Teams IP addresses on UDP 137
the IPS are 52.123.134.179  -  52.123.135.179 


Resolution : 

first of All these IPS related to Microsoft Teams as per the link here
Microsoft 365 URLs and IP address ranges - Microsoft 365 Enterprise | Microsoft Learn

we can say that it is not a normal behavior from Microsoft, but at least the environment is not compromised.
 

and to stop the unwanted connection we deactivated NetBIOS. 



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