Azure APIM - VNET injection vs inbound private endpoint, what is a difference?

Question

In the documentation, there are descriptions of VNET injection and Inbound private endpoints, but it is not clear to me what the difference between these two is. They seem very similar. Could someone please clarify the main differences and explain the scenarios in which each is useful? Can both variants be used for communication between two intranet systems?

Answer 1

The main difference between VNet injection

and inbound private endpoints

is the direction of traffic flow.

i.e.

VNet Injection controls both inbound and outbound traffic.

whereas

Private Endpoints only manage inbound traffic.

Therefore, the purpose of VNet Injection is it places the API Management instance inside a VNet, allowing secure inbound and outbound traffic. The instance is completely isolated within the virtual network, so it can access other resources in the VNet and connect securely to on-premise resources via VPN or ExpressRoute.

Use Case ?

This is useful when you need to control both inbound and outbound traffic, ensuring full network isolation. It’s especially helpful when connecting to on-premises networks via VPN or ExpressRoute.

whereas the purpose of private endpoint is to allows secure inbound connections to the API Management instance by providing a private IP address through Azure Private Link. It does not impact outbound traffic, which might still use the public internet unless additional routing is configured.

Use Case ?

This is useful when you want to restrict inbound access to private IPs, preventing data exfiltration and allowing specific VNets or private connections to access your API Management service.

References:

• Use a virtual network to secure inbound or outbound traffic for Azure API Management
• Integrate Azure services with virtual networks for network isolation