Azure Service Endpoint vs Private Endpoint: A Comprehensive Comparison

Azure Service Endpoints provide a secure and managed way to connect your Azure resources to your on-premises networks, allowing you to extend your on-premises network to Azure.

This is done through a managed gateway that connects to your on-premises network, enabling secure communication between your on-premises resources and Azure resources.

Azure Service Endpoints are easy to set up and manage, with a simple and straightforward configuration process.

They also support a wide range of Azure services, including Azure Storage, Azure Cosmos DB, and Azure SQL Database.

Private Endpoints, on the other hand, provide a more secure and isolated connection to your Azure resources, by creating a private IP address within your on-premises network.

This allows you to connect to your Azure resources as if they were on your on-premises network, with all the benefits of a private connection.

Service endpoints offer several key benefits that make them an attractive option for securing Azure service resources. They provide improved security by extending VNet identity to the service, allowing you to add a virtual network rule to secure resources.

One of the main advantages of service endpoints is that they enable optimal routing for Azure service traffic from your virtual network. This means that traffic is taken directly from your virtual network to the service on the Microsoft Azure backbone network, keeping it off the public internet.

Service endpoints are also simple to set up and require less management overhead. You don't need reserved, public IP addresses in your virtual networks to secure Azure resources through IP firewall, and there are no Network Address Translation (NAT) or gateway devices required.

Here are the key benefits of service endpoints at a glance:

Azure service endpoints provide a secure way to access Azure services, but it's essential to understand the implications on network traffic and access rules.

To secure Azure services to virtual networks, you need to enable service endpoints and add a virtual network rule. This switch allows you to access services without reserved public IP addresses used in IP firewalls.

With service endpoints, service traffic switches to use virtual network private addresses as the source IP addresses, which can cause existing Azure service firewall rules to stop working. Make sure to update your rules to allow for this switch.

If you want to allow traffic from on-premises networks, you must also allow public IP addresses from your on-premises or ExpressRoute. You can add these IP addresses through the IP firewall configuration for Azure service resources.

ExpressRoute users will need to identify the NAT IP addresses they're using and allow these public IP addresses in the resource IP firewall setting. For more information, see ExpressRoute NAT requirements.

Configuration and setup of Azure service endpoints is a straightforward process. You can configure service endpoints on a subnet in a virtual network, and they work with any type of compute instances running within that subnet.

To secure Azure service resources to virtual networks, you can configure multiple service endpoints for all supported Azure services on a subnet. This includes Azure Storage and Azure SQL Database, among others.

For Azure SQL Database, the virtual network where the endpoint is configured must be in the same region as the Azure service resource. For other services, you can secure Azure service resources to virtual networks in any region.

You can use service endpoints to secure new or existing resources to virtual networks, and the virtual network where the endpoint is configured can be in the same or different subscription than the Azure service resource.

Configuring service endpoints on a subnet in a virtual network allows you to secure Azure service resources to virtual networks. This works with any type of compute instances running within that subnet.

You can configure multiple service endpoints for all supported Azure services, such as Azure Storage or Azure SQL Database, on a subnet. This is a powerful feature that gives you flexibility in managing your Azure resources.

The virtual network where the endpoint is configured can be in the same or different subscription than the Azure service resource. This means you can set up endpoints across different subscriptions, which is useful for large-scale deployments.

For supported services, you can secure new or existing resources to virtual networks using service endpoints. This is a convenient option for managing your resources and securing them to virtual networks.

Here's a summary of the key points:

Provisioning is a crucial step in setting up your Azure service resources. To configure service endpoints on virtual networks, you'll need to have write access to the virtual network.

A user with write access can configure service endpoints independently, but to secure Azure service resources to a VNet, they must have permission to join subnets via service endpoints. This permission is included by default in built-in service administrator roles.

You can modify these permissions by creating custom roles, which allows you to assign specific permissions as needed. For more information on built-in roles, check out the Azure built-in roles documentation.

Virtual networks and Azure service resources can be in the same or different subscriptions. This flexibility makes it easier to set up and manage your resources, but be aware that not all Azure services support this setup.

When enabling a service endpoint, it's essential to consider the potential impact on your applications and network security. Any existing open TCP connections to the service are closed during the switch to a private IPv4 address.

To minimize disruptions, ensure that no critical tasks are running when enabling or disabling a service endpoint. This will prevent any potential losses of data or functionality.

The IP address switch only affects service traffic from your virtual network, leaving other traffic unaffected. This means that Azure services, if you have existing firewall rules using public IP addresses, will stop working after the switch.

Here are some key differences to keep in mind:

Let's dive into some real-world scenarios where Azure service endpoints can be super helpful. You can secure Azure services to multiple subnets within a virtual network or across multiple virtual networks by enabling service endpoints on each of the subnets independently.

To filter outbound traffic from a virtual network to Azure services, you can deploy a network virtual appliance within the virtual network and apply service endpoints to the subnet where it's deployed. This can be a game-changer if you want to inspect or filter traffic sent to an Azure service from your virtual network.

Directly deploying Azure services into specific subnets in a virtual network is another scenario where service endpoints can be useful. You can secure Azure service resources to managed service subnets by setting up a service endpoint on the managed service subnet.

Virtual Machine Disk traffic for managed and unmanaged disks isn't affected by service endpoints routing changes for Azure Storage. This includes diskIO as well as mount and unmount. You can limit REST access to page blobs to select networks through service endpoints and Azure Storage network rules.

Here are some key scenarios where Azure service endpoints can be applied:

Enabling a service endpoint can have some unexpected consequences. After enabling a service endpoint, the source IP addresses switch from using public IPv4 addresses to using their private IPv4 address when communicating with the service from that subnet.

This switch can cause existing open TCP connections to the service to be closed during the switch. This means you should ensure that no critical tasks are running when enabling or disabling a service endpoint to a service for a subnet.

The IP address switch only impacts service traffic from your virtual network, so other traffic addressed to or from the public IPv4 addresses assigned to your virtual machines will not be affected.

You'll also need to consider the impact on your firewall rules, as existing rules using Azure public IP addresses will stop working with the switch to virtual network private addresses.

DNS entries for Azure services remain unchanged, continuing to resolve to public IP addresses assigned to the Azure service.

If you're using network security groups (NSGs) with service endpoints, you'll need to take that into account as well.

Both Azure Service Endpoint and Private Endpoint allow for management and monitoring, but they have different approaches.

Azure Service Endpoint provides a single endpoint for access to a service, which can be monitored using Azure Monitor.

Private Endpoint, on the other hand, provides a secure and private connection to a service, allowing for more granular control over access and monitoring.

Private Endpoint can be monitored using Azure Monitor, but it also provides additional features for monitoring and logging, such as Azure Network Watcher.

VNet policies provide granular access control for virtual network traffic to Azure services.

You can use VNet service endpoint policies to filter virtual network traffic to Azure services. This filter allows only specific Azure service resources over service endpoints.

VNet service endpoint policies are useful for controlling access to Azure services.

For more information, see Virtual Network Service Endpoint Policies.

Logging and troubleshooting is a crucial part of managing and monitoring your Azure services. You can validate that the service endpoint route is in effect by checking the source IP address of any service request in the service diagnostics.

The source IP address for requests with service endpoints will show the virtual network private IP address, which is assigned to the client making the request from your virtual network. Without the endpoint, the address is an Azure public IP address.

Viewing the effective routes on any network interface in a subnet is another way to confirm the route to the service. Service endpoint routes override any BGP or user-defined routes (UDRs) for the address prefix match of an Azure service.

Azure Services provide a secure and direct connection to Azure services over an optimized route over the Azure backbone network. This is made possible by Service Endpoints.

Service Endpoints allow you to secure your critical Azure service resources to only your virtual networks. They enable private IP addresses in the VNet to reach the endpoint of an Azure service without needing a public IP address on the VNet.

To use Service Endpoint, you need to configure it on both the vNet and Storage Account sides. This is because Service Endpoint is a subnet level setting that connects to the public endpoint of the target service.

Using Service Endpoint avoids security concerns such as assigning a public IP address to your VM and allowing traffic from "all networks" for your Storage Account. Both of these scenarios are security risks.

Here are the key benefits of using Service Endpoint: