Understanding Azure Legacy and Its Impact on Your Apps

Azure Legacy is a collection of older Azure services that are still supported but no longer recommended for new deployments.

These services were introduced in the early days of Azure and have since been largely replaced by newer, more modern alternatives.

The impact of Azure Legacy on your apps can be significant, especially if you're still using older services that are no longer supported.

Azure Legacy services can make it difficult to take advantage of new features and technologies, which can limit your app's potential and make it harder to maintain.

App Service Environment version 1 and version 2, that use the Isolated v1 service plan, will be retired on August 31, 2024.

You can no longer create net new App Service Environment v1 and v2 resources as of January 29, 2024.

Migrate to App Service Environment v3 before August 31, 2024 to prevent resource deletion and data loss.

Please refer to product documentation for guidance on upgrading your App Service Environment.

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The Isolated v1 service plan is a legacy service plan that's being retired. It will be retired on August 31, 2024.

App Service Environment version 1 and version 2, which use this service plan, will also be retired on the same date. You can no longer create new resources using any method, including ARM/Bicep templates, Azure Portal, Azure CLI, or REST API, as of January 29, 2024.

You must migrate to App Service Environment v3 before August 31, 2024 to prevent resource deletion and data loss.

In addition to the Standard Service Plan, Azure Legacy Service Plans also offer the Basic Service Plan.

This plan is ideal for small applications and development environments, as it provides a more cost-effective option with a lower instance count.

The Basic Service Plan has a 1 small instance size, which is perfect for small applications that don't require a lot of resources.

With the Basic Service Plan, you can take advantage of a 3-day free trial, allowing you to test and evaluate the service before committing to a paid plan.

This plan is also a good choice for applications that require a fixed instance size, as it provides a predictable and stable environment.

Azure Legacy Service Plans also offer the Premium Service Plan, which is designed for large-scale applications and provides a higher instance count.

The Premium Service Plan has a 10 medium instance size, making it suitable for applications that require more resources and scalability.

To identify legacy authentication use in Azure, administrators can check for indicators in the sign-in logs. They can sign in to the Microsoft Entra admin center as at least a Reports Reader and browse to Identity > Monitoring & health > Sign-in logs.

To do this, they'll need to add the Client App column if it isn't shown by clicking on Columns > Client App. Then, they'll select Add filters > Client App > choose all of the legacy authentication protocols and select Apply. This will show sign-in attempts made by legacy authentication protocols.

Filtering shows you sign-in attempts made by legacy authentication protocols. Clicking on each individual sign-in attempt shows you more details. The Client App field under the Basic Info tab indicates which legacy authentication protocol was used.

To identify if your users have client apps that use legacy authentication, you can check for indicators in the sign-in logs. Sign in to the Microsoft Entra admin center as at least a Reports Reader to access these logs.

Browse to Identity > Monitoring & health > Sign-in logs to view the sign-in activity. Adding the Client App column by clicking on Columns > Client App is crucial to see which apps are using legacy authentication.

Select Add filters > Client App and choose all of the legacy authentication protocols to filter the sign-in attempts made by these protocols. Apply the filter to see the results.

Also, perform these steps on the User sign-ins (non-interactive) tab to get a comprehensive view. The Client App field under the Basic Info tab indicates which legacy authentication protocol was used for each sign-in attempt.

These logs indicate users who are using clients that depend on legacy authentication. You can use the Sign-ins using legacy authentication workbook to help triage legacy authentication within your tenant.

Use Multi-Factor Authentication to prevent unauthorized access to your Azure resources. This adds an extra layer of security by requiring users to provide a second form of verification, such as a code sent to their phone or a biometric scan.

Always use the most secure authentication protocols available, such as OAuth 2.0 and OpenID Connect. These protocols are designed to provide secure authentication and authorization for web applications and services.

Limit the use of Azure Legacy Authentication to only what is necessary, as it is being deprecated in favor of newer, more secure protocols. This will help ensure a smooth transition to more secure authentication methods.

Regularly review and update your Azure Active Directory settings to ensure that they align with your organization's security policies. This includes configuring conditional access policies and multi-factor authentication settings.

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Using Azure Legacy can bring a lot of benefits to your organization. With Azure, you can interconnect everything and relate data on the fly, which is a huge advantage.

Developers can leverage legacy core systems, middleware, and robotics using a microservice architecture driven by a powerful service mesh and extensible framework. This allows teams to deliver solutions into the platform and into the hands of their users in parallel.

Teams can deliver solutions rapidly, which is a key benefit. By leveraging Azure, insurance carriers can find new use cases and develop apps quickly, without disrupting existing architecture.

Projects can be secured and reused across the infrastructure, which accelerates digital transformation projects. This approach also provides a longer runway for decommissioning aging legacy systems.

Here are some specific benefits of using Azure Legacy: