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.