What Are Azure Network Security Groups?


Azure Network Security Groups (NSGs) filter network traffic to and from Azure resources in a virtual network. They filter both inbound and outbound traffic based on port, protocol, and source or destination IP address.

Understanding and utilizing NSGs well is crucial for maintaining robust network security in Azure. Azure is a very secure cloud service, but it is not impenetrable. Like all cloud platforms, the correct security protocols are required to make the most of these high security standards.

In 2023, 45% of companies who experienced a network security incident reported that it began on their cloud server. This is completely preventable. Your Azure service gives you all the tools you need to reduce your risk. To help you do that, this article will explore Network Security Groups and how they enhance Azure security.


How Do Network Security Groups in Azure Work?

Network Security Groups (NSGs) work by evaluating network traffic against a set of rules defined by you. These rules determine whether the program should allow or deny traffic. Here’s an overview of how this works.

  1. Rule Creation: You create and define rules in the NSG, specifying the allowed or denied traffic parameters.
  2. Priority Assignment: Each rule is assigned a priority. NSGs process rules in descending order of priority, from the lowest number (highest priority) to the highest number.
  3. Traffic Analysis: As traffic attempts to enter or exit a resource, NSGs analyze it against the defined rules.
  4. Action Enforcement: If the traffic matches a rule, the corresponding action (allow or deny) is enforced.

Azure NSGs also come with default security rules that provide a basic security level for your network. While you cannot remove these defaults, they operate at a lower priority than custom rules. This allows your custom configurations to override the defaults when necessary.


How to Create Azure Network Security Groups

Creating your own NSGs is a fairly straightforward process. Here’s a step-by-step guide to help you set up NSGs efficiently.

Log in to Azure

  1. Open your browser.
  2. Navigate to the Azure Portal at portal.azure.com.
  3. Enter your credentials to log in.

Navigate to the Network Security Groups Interface

  1. Once logged in, click on the hamburger icon (☰) in the top left corner.
  2. Scroll down and select “All services”.
  3. In the search box, type “Network Security Groups” and select it from the dropdown.

Create a New Security Group

  1. Click on the “+ Create” button.
  2. You will be directed to the “Create network security group” page under the Basics tab.

Configure the NSG

  1. Under Project details, select your Azure subscription.
  2. Choose an existing resource group or create a new one.
  3. For Instance details, enter a unique name for your NSG.
  4. Select the region where you want your NSG to be deployed.

Review & Create

  1. Review your settings for accuracy.
  2. Click on “Review + create”.
  3. After the validation passes, select “Create”.


Azure NSG Use Cases

Azure NSGs provide a way to implement customized security protocols for different scenarios in your cloud environment. They enable you to tailor security settings to specific requirements, which enhances both flexibility and protection.

Here is a table showcasing some practical applications of NSGs.


6 Helpful Azure NSG Best Practices

1. Apply NSGs to Virtual Network Subnets

Applying NSGs to specific Azure virtual network subnets allows for targeted security measures. This practice ensures that each subnet receives appropriate security rules for the data it holds. Thereby enhancing overall network protection.

2. Utilize Service Tags in NSG Rules

Service tags in network security group rules simplify the process of defining security boundaries. These tags allow you to easily specify Azure services in your NSG rules. That makes your security measures easier to manage.

3. Separate NSGs for Different Security Levels

Creating different NSGs for varying security levels allows for tailored security measures. This approach, known as the level network security group strategy, ensures that different areas of your Azure environment have appropriate protection.

4. Incorporate NSGs With Azure Load Balancer

Integrating NSGs with the Azure Load Balancer enhances protection and traffic management. This setup allows you to control traffic not only between the internet and your Azure environment but also among internal resources.

5. Optimize NSG for Various Subnets and Network Interfaces

Effectively configuring NSGs for both subnets and network interfaces ensures a more comprehensive security posture. This dual approach allows you to manage both broad and specific traffic rules that cover various aspects of your network infrastructure.

6. Regularly Update & Review NSG Rules

Regularly reviewing and updating your network security group rules ensures your Azure network remains secure. As your network needs to evolve, so should your NSG rules to reflect new security requirements and the current threat landscape.


Optimize How You Use Azure Network Security Groups With Expert Guidance

Exploring the capabilities of Azure Network Security Groups (NSGs) is just the beginning of enhancing your network’s security in Azure. While there’s a lot to learn, not everyone has the luxury of spare time.

If you want high-grade protection but don’t have the time to implement it yourself, you can count on Managed Azure Services from Atmosera. Our experts will help you use NSGs effectively and take care of their upkeep, so you can focus on your business priorities.

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