I have an web app in EU West Region that calls an API hosted in EU North Region. When I place my Web App in a VNet and call the web app in another region, that I do not control, I get a 403 Ip Forbidden.
For testing, I have setup 2 web apps. http://vnetazuretestnortheurope.azurewebsites.net/swagger/index.html and http://vnetazuretestwesteurope.azurewebsites.net/swagger/index.html
Using swagger you can create a server to server call by passing in a url. If you try with "https://api.bankintegration.dk" a web app I do not control or is part of the VNet, the result is not the same.
EU North (same region) the result is 200. EU West (cross region) the result is 403 Ip Forbidden.
If I remove the integration to the VNet from the EU West Web App, the request works.
Is the problem with Azure, my configuration or the remote API configuration?