Connect to a virtual network using Azure API Management
Azure API Management can be deployed inside an Azure virtual network (VNET) to access backend services within the network. For VNET connectivity options, requirements, and considerations, see Using a virtual network with Azure API Management.
This article explains how to set up VNET connectivity for your API Management instance in the external mode, where the developer portal, API gateway, and other API Management endpoints are accessible from the public internet. For configurations specific to the internal mode, where the endpoints are accessible only within the VNET, see Connect to an internal virtual network using Azure API Management.
This article uses the Azure Az PowerShell module, which is the recommended PowerShell module for interacting with Azure. To get started with the Az PowerShell module, see Install Azure PowerShell. To learn how to migrate to the Az PowerShell module, see Migrate Azure PowerShell from AzureRM to Az.
This feature is available in the Premium and Developer tiers of API Management.
Some prerequisites differ depending on the version (
stv1) of the compute platform hosting your API Management instance.
When you use the portal to create or update the network connection of an existing API Management instance, the instance is hosted on the
stv2 compute platform.
- An API Management instance. For more information, see Create an Azure API Management instance.
A virtual network and subnet in the same region and subscription as your API Management instance. The subnet may contain other Azure resources.
A network security group attached to the subnet above. A network security group (NSG) is required to explicitly allow inbound connectivity, because the load balancer used internally by API Management is secure by default and rejects all inbound traffic. For more strict configuration refer to Required ports below.
A Standard SKU public IPv4 address. The public IP address resource is required when setting up the virtual network for either external or internal access. With an internal virtual network, the public IP address is used only for management operations. Learn more about IP addresses of API Management.
The IP address must be in the same region and subscription as the API Management instance and the virtual network.
When creating a public IP resource, ensure you assign a "DNS Name Label" to it. The label you choose to use does not matter but a label is required if this resource will be assigned to an API Management Service.
The value of the IP address is assigned as the virtual public IPv4 address of the API Management instance in that region.
When changing from an external to internal virtual network (or vice versa), changing subnets in the network, or updating availability zones for the API Management instance, you must configure a different public IP address.
Enable VNET connection
Enable VNET connectivity using the Azure portal (
stv2 compute platform)
Go to the Azure portal to find your API management instance. Search for and select API Management services.
Choose your API Management instance.
Select Virtual network.
Select the External access type.
In the list of locations (regions) where your API Management service is provisioned:
- Choose a Location.
- Select Virtual network, Subnet, and IP address.
The VNET list is populated with Resource Manager VNETs available in your Azure subscriptions, set up in the region you are configuring.
Select Apply. The Virtual network page of your API Management instance is updated with your new VNET and subnet choices.
Continue configuring VNET settings for the remaining locations of your API Management instance.
In the top navigation bar, select Save, then select Apply network configuration.
It can take 15 to 45 minutes to update the API Management instance.
Enable connectivity using a Resource Manager template
Use the following templates to deploy an API Management instance and connect to a VNET. The templates differ depending on the version (
stv1) of the compute platform hosting your API Management instance.
Connect to a web service hosted within a virtual network
Once you've connected your API Management service to the VNET, you can access backend services within it just as you do public services. When creating or editing an API, type the local IP address or the host name (if a DNS server is configured for the VNET) of your web service into the Web service URL field.
Review the following sections for more network configuration settings.
These settings address common misconfiguration issues that can occur while deploying API Management service into a VNET.
Custom DNS server setup
In external VNET mode, Azure manages the DNS by default. You can optionally configure a custom DNS server. The API Management service depends on several Azure services. When API Management is hosted in a VNET with a custom DNS server, it needs to resolve the hostnames of those Azure services.
- For guidance on custom DNS setup, including forwarding for Azure-provided hostnames, see Name resolution for resources in Azure virtual networks.
- For reference, see the required ports and network requirements.
If you plan to use a custom DNS server(s) for the VNET, set it up before deploying an API Management service into it. Otherwise, you'll need to update the API Management service each time you change the DNS Server(s) by running the Apply Network Configuration Operation.
You can control inbound and outbound traffic into the subnet in which API Management is deployed by using network security group rules. If certain ports are unavailable, API Management may not operate properly and may become inaccessible.
When an API Management service instance is hosted in a VNET, the ports in the following table are used. Some requirements differ depending on the version (
stv1) of the compute platform hosting your API Management instance.
Bold items in the Purpose column indicate port configurations required for successful deployment and operation of the API Management service. Configurations labeled "optional" are only needed to enable specific features, as noted. They are not required for the overall health of the service.
|Source / Destination Port(s)||Direction||Transport protocol||Service Tags
Source / Destination
|Purpose (*)||VNET type|
|* / , 443||Inbound||TCP||INTERNET / VIRTUAL_NETWORK||Client communication to API Management (optional)||External|
|* / 3443||Inbound||TCP||ApiManagement / VIRTUAL_NETWORK||Management endpoint for Azure portal and PowerShell (optional)||External & Internal|
|* / 443||Outbound||TCP||VIRTUAL_NETWORK / Storage||Dependency on Azure Storage||External & Internal|
|* / 443||Outbound||TCP||VIRTUAL_NETWORK / AzureActiveDirectory||Azure Active Directory and Azure Key Vault dependency (optional)||External & Internal|
|* / 1433||Outbound||TCP||VIRTUAL_NETWORK / SQL||Access to Azure SQL endpoints||External & Internal|
|* / 443||Outbound||TCP||VIRTUAL_NETWORK / AzureKeyVault||Access to Azure Key Vault||External & Internal|
|* / 5671, 5672, 443||Outbound||TCP||VIRTUAL_NETWORK / Event Hub||Dependency for Log to Event Hub policy and monitoring agent (optional)||External & Internal|
|* / 445||Outbound||TCP||VIRTUAL_NETWORK / Storage||Dependency on Azure File Share for GIT (optional)||External & Internal|
|* / 443, 12000||Outbound||TCP||VIRTUAL_NETWORK / AzureCloud||Health and Monitoring Extension (optional)||External & Internal|
|* / 1886, 443||Outbound||TCP||VIRTUAL_NETWORK / AzureMonitor||Publish Diagnostics Logs and Metrics, Resource Health, and Application Insights (optional)||External & Internal|
|* / 25, 587, 25028||Outbound||TCP||VIRTUAL_NETWORK / INTERNET||Connect to SMTP Relay for sending e-mail (optional)||External & Internal|
|* / 6381 - 6383||Inbound & Outbound||TCP||VIRTUAL_NETWORK / VIRTUAL_NETWORK||Access Redis Service for Cache policies between machines (optional)||External & Internal|
|* / 4290||Inbound & Outbound||UDP||VIRTUAL_NETWORK / VIRTUAL_NETWORK||Sync Counters for Rate Limit policies between machines (optional)||External & Internal|
|* / 6390||Inbound||TCP||AZURE_LOAD_BALANCER / VIRTUAL_NETWORK||Azure Infrastructure Load Balancer||External & Internal|
To enable TLS/SSL certificate chain building and validation, the API Management service needs outbound network connectivity to
crl.microsoft.com. This dependency is not required if any certificate you upload to API Management contains the full chain to the CA root.
Outbound access on
port 53 is required for communication with DNS servers. If a custom DNS server exists on the other end of a VPN gateway, the DNS server must be reachable from the subnet hosting API Management.
Metrics and health monitoring
Outbound network connectivity to Azure Monitoring endpoints, which resolve under the following domains, are represented under the AzureMonitor service tag for use with Network Security Groups.
|Azure China 21Vianet||
Regional service tags
NSG rules allowing outbound connectivity to Storage, SQL, and Event Hubs service tags may use the regional versions of those tags corresponding to the region containing the API Management instance (for example, Storage.WestUS for an API Management instance in the West US region). In multi-region deployments, the NSG in each region should allow traffic to the service tags for that region and the primary region.
Enable publishing the developer portal for an API Management instance in a VNET by allowing outbound connectivity to blob storage in the West US region. For example, use the Storage.WestUS service tag in an NSG rule. Currently, connectivity to blob storage in the West US region is required to publish the developer portal for any API Management instance.
Allow outbound network connectivity for the SMTP Relay, which resolves under the host
Only the SMTP relay provided in API Management may be used to send email from your instance.
Developer portal CAPTCHA
Allow outbound network connectivity for the developer portal's CAPTCHA, which resolves under the hosts
Azure portal diagnostics
When using the API Management extension from inside a VNET, outbound access to
port 443 is required to enable the flow of diagnostic logs from Azure portal. This access helps in troubleshooting issues you might face when using extension.
Azure load balancer
You're not required to allow inbound requests from service tag
AZURE_LOAD_BALANCER for the
Developer SKU, since only one compute unit is deployed behind it. But inbound from
AZURE_LOAD_BALANCER becomes critical when scaling to a higher SKU, like
Premium, as failure of health probe from load balancer then blocks all Inbound access to control plane and data plane.
When adding virtual machines running Windows to the VNET, allow outbound connectivity on port 1688 to the KMS endpoint in your cloud. This configuration routes Windows VM traffic to the Azure Key Management Services (KMS) server to complete Windows activation.
Force tunneling traffic to on-premises firewall Using ExpressRoute or Network Virtual Appliance
Commonly, you configure and define your own default route (0.0.0.0/0), forcing all traffic from the API Management-delegated subnet to flow through an on-premises firewall or to a network virtual appliance. This traffic flow breaks connectivity with Azure API Management, since outbound traffic is either blocked on-premises, or NAT'd to an unrecognizable set of addresses no longer working with various Azure endpoints. You can solve this issue via a couple of methods:
Enable service endpoints on the subnet in which the API Management service is deployed for:
- Azure SQL
- Azure Storage
- Azure Event Hub
- Azure Key Vault (v2 platform)
By enabling endpoints directly from API Management subnet to these services, you can use the Microsoft Azure backbone network, providing optimal routing for service traffic. If you use service endpoints with a force tunneled API Management, the above Azure services traffic isn't force tunneled. The other API Management service dependency traffic is force tunneled and can't be lost. If lost, the API Management service would not function properly.
All the control plane traffic from the internet to the management endpoint of your API Management service is routed through a specific set of inbound IPs, hosted by API Management. When the traffic is force tunneled, the responses will not symmetrically map back to these inbound source IPs. To overcome the limitation, set the destination of the following user-defined routes (UDRs) to the "Internet", to steer traffic back to Azure. Find the set of inbound IPs for control plane traffic documented in Control Plane IP Addresses.
For other force tunneled API Management service dependencies, resolve the hostname and reach out to the endpoint. These include:
- Metrics and Health Monitoring
- Azure portal Diagnostics
- SMTP Relay
- Developer portal CAPTCHA
- Azure KMS server
- A load-balanced public IP address (VIP) is reserved to provide access to all service endpoints and resources outside the VNET.
- Load balanced public IP addresses can be found on the Overview/Essentials blade in the Azure portal.
- An IP address from a subnet IP range (DIP) is used to access resources within the VNET.
The VIP address(es) of the API Management instance will change when:
- The VNET is enabled or disabled.
- API Management is moved from External to Internal virtual network mode, or vice versa.
- Zone redundancy settings are enabled, updated, or disabled in a location for your instance (Premium SKU only).
Control plane IP addresses
The following IP addresses are divided by Azure Environment. When allowing inbound requests, IP addresses marked with Global must be permitted, along with the Region-specific IP address. In some cases, two IP addresses are listed. Permit both IP addresses.
|Azure Environment||Region||IP address|
|Azure Public||South Central US (Global)||126.96.36.199|
|Azure Public||North Central US (Global)||188.8.131.52|
|Azure Public||Australia Central||184.108.40.206|
|Azure Public||Australia Central 2||220.127.116.11|
|Azure Public||Australia East||18.104.22.168|
|Azure Public||Australia Southeast||22.214.171.124|
|Azure Public||Brazil South||126.96.36.199, 188.8.131.52|
|Azure Public||Brazil Southeast||184.108.40.206|
|Azure Public||Canada Central||220.127.116.11, 18.104.22.168|
|Azure Public||Canada East||22.214.171.124|
|Azure Public||Central India||126.96.36.199, 188.8.131.52|
|Azure Public||Central US||184.108.40.206|
|Azure Public||Central US EUAP||220.127.116.11|
|Azure Public||East Asia||18.104.22.168|
|Azure Public||East US||22.214.171.124|
|Azure Public||East US 2||126.96.36.199|
|Azure Public||East US 2 EUAP||188.8.131.52|
|Azure Public||France Central||184.108.40.206|
|Azure Public||France South||220.127.116.11|
|Azure Public||Germany North||18.104.22.168|
|Azure Public||Germany West Central||22.214.171.124, 126.96.36.199|
|Azure Public||Japan East||188.8.131.52|
|Azure Public||Japan West||184.108.40.206|
|Azure Public||India Central||220.127.116.11|
|Azure Public||India West||18.104.22.168|
|Azure Public||Korea Central||22.214.171.124, 126.96.36.199|
|Azure Public||Korea South||188.8.131.52|
|Azure Public||North Central US||184.108.40.206|
|Azure Public||North Europe||220.127.116.11|
|Azure Public||Norway East||18.104.22.168|
|Azure Public||Norway West||22.214.171.124|
|Azure Public||South Africa North||126.96.36.199, 188.8.131.52|
|Azure Public||South Africa West||184.108.40.206|
|Azure Public||South Central US||220.127.116.11, 18.104.22.168|
|Azure Public||South India||22.214.171.124|
|Azure Public||Southeast Asia||126.96.36.199|
|Azure Public||Switzerland North||188.8.131.52|
|Azure Public||Switzerland West||184.108.40.206|
|Azure Public||UAE Central||220.127.116.11|
|Azure Public||UAE North||18.104.22.168|
|Azure Public||UK South||22.214.171.124|
|Azure Public||UK West||126.96.36.199|
|Azure Public||West Central US||188.8.131.52|
|Azure Public||West Europe||184.108.40.206|
|Azure Public||West India||220.127.116.11|
|Azure Public||West US||18.104.22.168|
|Azure Public||West US 2||22.214.171.124|
|Azure Public||West US 3||126.96.36.199|
|Azure China 21Vianet||China North (Global)||188.8.131.52|
|Azure China 21Vianet||China East (Global)||184.108.40.206|
|Azure China 21Vianet||China North||220.127.116.11|
|Azure China 21Vianet||China East||18.104.22.168|
|Azure China 21Vianet||China North 2||22.214.171.124|
|Azure China 21Vianet||China East 2||126.96.36.199|
|Azure Government||USGov Virginia (Global)||188.8.131.52|
|Azure Government||USGov Texas (Global)||184.108.40.206|
|Azure Government||USGov Virginia||220.127.116.11|
|Azure Government||USGov Iowa||18.104.22.168|
|Azure Government||USGov Arizona||22.214.171.124|
|Azure Government||USGov Texas||126.96.36.199|
|Azure Government||USDoD Central||188.8.131.52|
|Azure Government||USDoD East||184.108.40.206|
Unsuccessful initial deployment of API Management service into a subnet
- Deploy a virtual machine into the same subnet.
- Connect to the virtual machine and validate connectivity to one of each of the following resources in your Azure subscription:
- Azure Storage blob
- Azure SQL Database
- Azure Storage Table
- Azure Key Vault (for an API Management instance hosted on the
After validating the connectivity, remove all the resources in the subnet before deploying API Management into the subnet (required when API Management is hosted on the
Verify network connectivity status
- After deploying API Management into the subnet, use the portal to check the connectivity of your instance to dependencies, such as Azure Storage.
- In the portal, in the left-hand menu, under Deployment and infrastructure, select Network connectivity status.
Filter Description Required Select to review the required Azure services connectivity for API Management. Failure indicates that the instance is unable to perform core operations to manage APIs. Optional Select to review the optional services connectivity. Failure indicates only that the specific functionality will not work (for example, SMTP). Failure may lead to degradation in using and monitoring the API Management instance and providing the committed SLA.
To address connectivity issues, review network configuration settings and fix required network settings.
When making changes to your network, refer to NetworkStatus API to verify that the API Management service has not lost access to critical resources. The connectivity status should be updated every 15 minutes.
Resource navigation links
An APIM instance hosted on the
stv1compute platform, when deployed into a Resource Manager VNET subnet, reserves the subnet by creating a resource navigation link. If the subnet already contains a resource from a different provider, deployment will fail. Similarly, when you delete an API Management service, or move it to a different subnet, the resource navigation link will be removed.
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