Navigating the complexities of Azure requires a solid grasp of network connectivity. It forms the backbone of seamless interactions between your resources, ensuring a robust and secure environment. Azure offers two powerful solutions – Azure Private Link and Azure Service Endpoint. Understanding their features, use cases, and potential pitfalls can simplify your decision-making process.
In this article, we will discover the nuances of Azure Private Link and Azure Service Endpoint to make informed decisions for your network connectivity. Then we learn when to use each option, their features, and when to avoid them to simplify your Azure networking choices for optimal performance and security!
In This Article
Understanding Azure Private Link
Azure Private Link (Private Endpoint) is a game-changer, enabling private access to Azure services directly from your virtual network. It establishes a private endpoint within your Virtual Network (VNet), granting secure connectivity to services hosted in Azure’s public cloud.
Whether it’s accessing Azure SQL Database, Storage, or other PaaS services, Azure Private Link ensures a secure and efficient connection. It’s an ideal solution for businesses prioritizing data privacy and regulatory compliance.
Let’s take a quick look at the Azure Private Endpoint architecture diagram below. The private endpoint is a resource that you define on a subnet. You can define multiple private endpoints that point to the same resource if you want to get to the resource from multiple subnets and/or virtual networks across your Azure subscriptions.
You should know that by default, network security group (NSG) rules that may be associated with that subnet will be disabled for private endpoints. In other words, private endpoints will not be affected by network security group rules, it will ignore them. Now that’s not going to affect any other traffic. In other words, the NSG enforcement will work just fine for the VMs that are on the subnet, it’s just the private endpoint will ignore them.
When you create a private endpoint, the communication with that specific resource is happening on the Azure backplane and there is no inbound Internet access allowed.
The good news is, that in summer 2022, Microsoft announced that you can use network policies like UDR (User Defined Route) and NSG (Network Security Group) with Private Endpoints. For this to work, you have to enable network policy support at the subnet level, as shown in the figure below. Because, as we just mentioned, by default the network policy is disabled, and private endpoints will not be affected by network security group rules, it will ignore them.
You have to enable the Private Endpoint Network Policy if you want to use NSG and UDR. This feature enhancement provides you with the ability to enable advanced security controls on traffic destined to a private endpoint.
When to Use Azure Private Link?
You use Azure Private Link (Private Endpoint) to secure and private access to Azure services, especially when data security and privacy are top priorities. It’s ideal in scenarios where public internet access to Azure services is restricted.
The main features offered by Private Link:
- Private Connectivity: Establish a private link to Azure services.
- Data Privacy: Ensure data doesn’t traverse the public internet, enhancing security.
- Compliance Assistance: Facilitates compliance requirements by maintaining a secure, private connection.
However, it’s not recommended when:
- Cost is a Primary Concern: In cases where the expense outweighs the benefits, especially compared to public endpoints.
- Services Don’t Require Strict Private Access: If your services can function well with public connectivity.
Related: Check out Designing and Implementing Microsoft Azure Networking Solutions.
Understanding Azure Service Endpoint
Azure Service Endpoint allows your virtual network resources to privately communicate with Azure services over the Microsoft backbone network. This optimizes performance and reduces data exposure to potential threats.
From integrating with Azure Storage to connecting with Azure SQL Database, Service Endpoint streamlines communication, improving latency and efficiency. It’s tailored for organizations seeking a balance between performance and security.
Now, given that a data product that you’re interested in is on the supported list by service endpoints. How do these work, to protect access to your Azure data product?
What’s happening, is that you’re constraining outbound traffic from a virtual network to public Azure Data Services by using Private IPs. What we have with service endpoints, is you’re creating an exception in your virtual networks at the subnet level, that would allow connectivity to certain Azure resource providers.
Let’s take the example on the diagram below, we have a virtual network at left, the 10.1.0.0/16 virtual network, and we see the service endpoint that reaches out to Azure Storage. Now what’s not entirely obvious in this topology diagram, is that the Azure Storage account is still available on the Internet, it’s just that functionally Inbound access from the Internet is being blocked, and the only traffic that’s being allowed into that storage account, is coming out of the virtual network using a private, non‑routable IP address.
You can also define multiple service endpoints on peered virtual networks, but the main point we want to draw to you is what we mentioned previously, when you create a service endpoint in a virtual network, and then you place that resource on the service endpoint, in this example, it’s a storage account, that resource remains accessible on its public IP address, even though it’s not accepting inbound traffic from the internet.
So, by using virtual network Service Endpoints, you extend your private address space in Azure, by providing a direct connection to your Azure services. Service Endpoints, let you secure your Azure resources to only your virtual network. In this way, Service traffic will remain on the Azure backbone and will not go out to the Internet.
When to Use Azure Service Endpoint?
You opt for Azure Service Endpoint when you need to secure Azure services exclusively to your Virtual Network (VNet). It ensures that data traffic remains within the Microsoft Azure backbone network.
The main features offered by Service Endpoint:
- Secure Azure Service Resources: Limit access to Azure service resources to only your VNet.
- Direct Traffic through Microsoft’s Backbone Network: Utilize Microsoft’s backbone network for efficient data transmission.
- Simplified Network Configuration: Streamline network configuration by removing public internet routes.
However, it’s not recommended when:
- Fully Private Connection Needed: If a connection entirely avoiding the public internet is crucial, even within Microsoft’s backbone.
- Accessing Azure Services Outside Your Region: In scenarios where Azure services beyond your region need to be accessed.
Choosing the Right Solution
To simplify your network connectivity decision-making:
> Use Azure Private Link for scenarios demanding the highest level of security and privacy, where data should not traverse the public internet at all.
> Use Azure Service Endpoint for secure, cost-effective connectivity, where traffic remains on Microsoft’s network but can traverse through their public backbone.
Making decisions about Azure networking services can be challenging, but these insights can help:
> Cost Consideration: Evaluate your budgetary constraints before opting for Azure Private Link, as it can be more expensive. Check Azure Private Link pricing.
> Geographical Accessibility: If your Azure services span multiple regions, consider Azure Service Endpoint for broader accessibility.
Frequently Asked Questions (FAQs)
What makes Azure Private Link a preferred choice for security?
Azure Private Link ensures a completely private connection to Azure services, eliminating any exposure to the public internet, and making it ideal for scenarios where data security is paramount.
Can Azure Service Endpoint be cost-effective for small-scale applications?
Absolutely! Azure Service Endpoint provides a secure, cost-effective solution for connectivity within Microsoft’s network, making it suitable for various applications, including smaller-scale ones.
Is Compliance easier to achieve with Azure Private Link?
Yes, Azure Private Link aids in meeting compliance requirements by offering a secure and private connection to Azure services, ensuring data privacy. Azure Private Link establishes a private connection, ensuring that data travels securely within the Azure network without exposure to the public internet.
Can Azure Service Endpoint be used for accessing Azure services globally?
While Azure Service Endpoint is excellent for securing connections within Microsoft’s backbone, it may not be optimal for accessing Azure services outside your region. Consider this limitation for global accessibility.
How can I balance security and cost-effectiveness in my Azure network?
To balance security and cost, consider the specific needs of your application. Choose Azure Private Link for heightened security and Azure Service Endpoint for a secure, cost-effective option.
Are there any geographical limitations when using Azure Private Link?
No, Azure Private Link does not have geographical restrictions, providing a robust solution for secure connections across different regions.
Can I use both Private Link and Service Endpoint simultaneously?
Yes, depending on your requirements, you can leverage both solutions for different services within your Azure environment.
Is Azure Service Endpoint suitable for high-traffic scenarios?
Yes, Azure Service Endpoint, utilizing the Microsoft backbone network, is well-suited for high-traffic scenarios, ensuring optimal performance.
The choice between Azure Private Link and Azure Service Endpoint emerges as a pivotal decision for businesses navigating the complexities of network connectivity. Each option brings its unique strengths, with Azure Private Link excelling in delivering an unparalleled level of security and privacy, especially crucial for scenarios where data should remain shielded from the public internet. On the other hand, Azure Service Endpoint offers a cost-effective solution that ensures secure connectivity within Microsoft’s network, balancing efficiency and budget considerations.
When working with Azure networking, it is important to make choices that align with your application’s specific needs. Azure Private Link stands as the go-to option when an uncompromising level of security is non-negotiable, while Azure Service Endpoint provides a secure, budget-conscious alternative for scenarios where connectivity within Microsoft’s network suffices.
Hope this simplifies your decision-making for Azure networking services! Share your thoughts, tips, or favorites in the comments section below.
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