I have an App Service (currently under development so no heavy traffic) on Azure. It connects to a Google Cloud DB. Yesterday for no apparent reason, the Outbound IP addresses of the App Service all changed causing the connection between Azure and Google to fall over.
We haven't scaled the app or made any large configuration changes.
I'm just wondering for what reason(s) the Outbound IP addresses might change on Azure with seemingly no warning? Has anyone experienced this?
Thanks for any insight.
Update
Just to clarify – I am aware of the range of IPs (accessible via the App Serivce > Properties > Outbound IP Addresses) but in this case they ALL changed without notice.
Best Answer
Azure App Service does not support fixed outbound IP due to its architecture considerations, instead, you have a range of IPs that could be used. To see the list of these IPs:
Note that you also get an external IP address if you configure a Custom Domain, but this is related to INBOUND connections only.
If you want your own set of outbound IPs or really need a fixed one, consider App Service Environment.
Update:
https://blogs.msdn.microsoft.com/benjaminperkins/2016/03/02/how-to-find-you-outgoing-azure-app-service-ip-address/
Static Outbound IP without ASE - Still Under Review
https://feedback.azure.com/forums/169385-web-apps-formerly-websites/suggestions/16790656-add-static-ip-address-for-outbound-traffic-without