NSGs are a set of security rules applied on your Azure network resources. They are the main tool to enforce and control network traffic rules for your resources. NSGs can be applied to two types of resources: subnets and NICs. If an NSG is applied to a subnet, the rules will be applied to all devices that are connected to that subnet. When an NSG is applied to an NIC, the rules will be applied only for that device.
In the overview of the NSG blade, we can see all the rules that are currently applied, both inbound and outbound. By default, all inbound traffic from outside is disabled, except port 3389, which allows us to connect to the VM remotely. All inbound traffic coming from inside the virtual network or Azure ...
