Update documentation: IP Addresese of APIM service in VNET
We found this documentation a bit confusing https://docs.microsoft.com/en-us/azure/api-management/api-management-howto-ip-addresses#ip-addresses-of-api-management-service-in-vnet
1) If your API Management service is inside a virtual network, it will have two types of IP addresses - public and private.
2) Public IP addresses are used for internal communication on port 3443 - for managing configuration (for example, through Azure Resource Manager). In the external VNet configuration, they are also used for runtime API traffic. When a request is sent from API Management to a public-facing (Internet-facing) backend, a public IP address will be visible as the origin of the request.
3) Private virtual IP (VIP) addresses, available only in the internal VNet mode, are used to connect from within the network to API Management endpoints - gateways, the developer portal, and the management plane for direct API access. You can use them for setting up DNS records within the network.
We see 3 issues here ^:
Paragraph 1) in conflict with Paragraph 3) regarding the availability of private IP address. 1) Implies that Private IP address available for both: external and internal. Latter implies - only internal.
We would expect an extra paragraph between 2) and 3) whcih explains how APIm in external mode makes a call to the resources inside a VNET (for example how it will do DNS resolution w/o having an IP address which is phisically resides within VNET itself)
In out case we don't see Private IP address (like on the screenshot) in Azure portal if we configure APIM in external mode