Introduction to ASGs
In a nutshell, ASGs follow the application’s structure or tiers and allow you to group both network security policies and VMs based on specific application groups. These ASGs can then be used as sources or destination rules within NSGs. This is an incredibly powerful feature, as this allows you to automatically apply security rules to network interfaces, no matter the IP address or overall subnet membership!
Both NSGs and ASGs bring multiple benefits to the area of network security, greatly simplifying and unifying the management experience while increasing the flexibility and agility of your architecture. For a deeper understanding of ASGs, be sure to review this additional reading: https://docs.microsoft.com/azure/virtual-network/application-security-groups.
Now that we have completed an overview of NSGs and ASGs, let’s continue by gaining an overview of another incredible feature – Azure service tags.