Azure - Application Security Groups (ASG)

Introduction

• Application Security Groups (ASGs) in Azure provide a way to manage and group network security rules in a more flexible and scalable manner.
• They allow you to define and enforce security policies based on the role and function of the application rather than individual IP addresses.

How ASGs Work

1. Create ASGs:
   • You create ASGs to represent different roles within your application. For example, ASG-Web, ASG-App, and ASG-DB for web servers, application servers, and database servers, respectively.
2. Assign VMs to ASGs:
   • Assign the network interfaces of your VMs to the appropriate ASGs. A VM’s NIC can be associated with one or more ASGs.
3. Define NSG Rules Using ASGs:
   • Create NSG rules using ASGs as the source and destination. For example, you can create a rule that allows HTTP traffic from ASG-Web to ASG-App, or SQL traffic from ASG-App to ASG-DB.

Benefits of ASGs

1. Scalability: Easily scale your application by adding or removing VMs from ASGs without modifying NSG rules.
2. Manageability: Simplify the management of NSG rules by using logical groups instead of IP addresses.
3. Flexibility: Dynamically adjust to changes in your application architecture.
4. Security: Enforce security policies based on the application’s architecture, ensuring only necessary traffic flows between different tiers of the application.