Error when creating listener on Application Gateway

Question

Tier - Standard
SKU - Small

Both a public and private Frontend IP configuration are setup.

I first created a listener using the public Frontend IP and port 443 (HTTPS). I chose a listener type of Multi site and entered a host name. The listener created successfully.

Next, I attempted to created a listener using the private Frontend IP and port 443 (HTTPS). I chose a listener type of Multi site and entered a host name. The listener failed to create with an error:

"Failed to save configuration changes to application gateway. Error: Two Http Listeners of Application Gateway are using the same Frontend Port.

I was able to create additional listeners on the public Frontend IP using port 443 with a listener type of Multi site.

Is it a product limitation to not be able to create a public and private listener on the same port?

Answer 1

Hello @Brad Vest ,

Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.

Yes, it is a product limitation to not be able to create a public and private listener on the same port.
Please refer : https://learn.microsoft.com/en-us/azure/application-gateway/application-gateway-faq#can-i-use-the-same-port-for-both-public-facing-and-private-facing-listeners

If you wish you may vote in the below forums requesting this feature. All the feedback shared in these forums are monitored and reviewed by the Microsoft engineering teams responsible for building Azure.
https://feedback.azure.com/forums/217313-networking/suggestions/34687048-azure-appgateway-same-port-cant-be-used-on-both-pr
https://feedback.azure.com/forums/217313-networking/suggestions/39166876-allow-public-and-private-ip-to-have-its-own-listen

Kindly let us know if the above helps or you need further assistance on this issue.

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