Creating and evaluating security rules with Azure Portal
- First, go the overview page of the NSG. In there, you can see the default inbound and outbound security rules:
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- Then, under Settings, select Inbound security rules to add a custom rule. Then click Add in the top menu:
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- We are going to deny all traffic over port 3389, which is the RDP port. Therefore, we select the Service Tag for Source field and the Internet for Source service tag, set the destination to VirtualNetwork and the destination port ranges to 3389 over any protocol. The action will be set to Deny. We are going to set the priority to 100, which is the highest priority:
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- Click Add.
- We have now created an inbound security rule that denies all RDP traffic. This rule is bound to the subnet, because we associated this NSG with a subnet.
- To evaluate this security rule, deploy a VM inside this resource group, virtual network, and subnet. Also, enable RDP for it. After deployment, try connecting to it. If the security rule got applied correctly, you should receive the following error message:
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