Outbound Dependencies for Function Apps in Elastic Premium Plan with VNET Integration and Forced Tunnelling to Firewall

Question

Is there any Microsoft article which outlines which outbound traffic (IP/Ports/FQDNs/Wild Cards) must be allowed on the Firewall for Function Apps with VNET Integration and Forced Tunnelling to that Third Party Firewall? I am able to find decent documentation for the scenario on App Service Environment (https://learn.microsoft.com/en-us/azure/app-service/environment/firewall-integration#configuring-third-party-firewall-with-your-ase), but there is nothing available for Function Apps with VNET Integration and Forced Tunnelling to Third Party Firewall, or even for outbound traffic to be allowed for NSG based outbound traffic control. Would be great if someone can point me to the Microsoft Documentation for Outbound Dependencies for Function Apps with VNET Integration on Elastic Premium / similar plans.

Answer 1

ZQadir Thanks for posting your question in Microsoft Q&A. As described in this comment, Azure Functions does not have any such dependencies and you only need to allow-list (whitelist) an endpoint that your app requires.

Note: the app can still make outbound calls to the internet by default for a function app in Premium plan within a VNET (Outbound IP restrictions). I think it is good to add a note describing the same and will pass this feedback internally to our doc authoring team.

I hope this helps and let me know if you have any questions.

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