All inbound request port to Azure Linux Webapp is 80, not 443 in logs( in application insights & AppServiceHTTPLogs Table)

Question

All inbound request port to Azure Linux Webapp is 80, not 443 in logs( in application insights & AppServiceHTTPLogs Table)

Gallatin 21V 186

We made request test to azure linux webapp, find all port is 80, no matter I request http or https.

I configed the Diagnostic logs and application insights, the recored was same as below:

(Made same test in windows webapp, there is no this issue. Please help confirm whether this is a bug or bydisgn?)

Diagnostic logs AppServiceHTTPLogs：

Bhargavi Naragani 3,075 Reputation points Microsoft External Staff

2025-04-24T06:28:09.9233333+00:00

Hi @Gallatin 21V ,
It seems that your observation of all inbound requests to your Azure Linux Web App being logged on port 80, regardless of whether the requests were made via HTTP or HTTPS, could be due to how Azure handles incoming traffic. In Azure App Service, HTTP traffic is typically served on port 80, while HTTPS traffic is served on port 443. However, when HTTPS requests are made, they are often redirected to HTTP for logging purposes, which might explain why you see only port 80 in your logs.

This behavior could be by design, particularly if there are specific configurations or settings applied to your Linux Web App that differ from those of the Windows Web App. It is advisable to review the configuration settings of your Linux Web App to ensure that HTTPS is properly set up and that any necessary SSL certificates are correctly configured.

App Service networking features
App Service Environment networking

Hope this information is helpful, let me know if you have any further queries.
Gallatin 21V 186 Reputation points

2025-04-24T07:26:00.68+00:00

Hi @Bhargavi Naragani , thanks for your quick reply . But it might cloud not explian that when I request windows webapp, it can be record corrcetly. I request https , ports in logs is 443, requset http, ports in logs is 80. Is there any difference when log request for windows webapp and linux webapp?
Bhargavi Naragani 3,075 Reputation points Microsoft External Staff

2025-04-24T07:51:08.8+00:00

Hi @Gallatin 21V

All-incoming requests to your Azure Linux Web App are being logged with port 80, regardless of whether the requests were made using HTTP or HTTPS. This was confirmed through Application Insights logs and AppServiceHTTPLogs (Diagnostic Logs)

The same tests on an Azure Windows Web App do show correct ports, port 443 for HTTPS and port 80 for HTTP. So, this is a real and known behavior difference between Azure Linux and Windows Web Apps. It is not a bug, but rather by design due to how request routing and logging are handled in the underlying infrastructure of Azure App Service for Linux.

When you make an HTTPS request to an Azure App Service, Azure terminates TLS at the front-end load balancer. This means the load balancer decrypts the HTTPS request then forwards the request to the app over HTTP internally (i.e., on port 80). As a result, the app and logging layers (e.g., AppServiceHTTPLogs, Application Insights) only see port 80, not the original 443.

This behavior is specific to Azure App Service on Linux. In contrast, Windows App Services handle the logging stack differently, and the original client port (443) is preserved and visible in logs like AppServiceHTTPLogs.

Your answer

Bhargavi Naragani 3,075 Reputation points Microsoft External Staff

2025-04-24T06:28:09.9233333+00:00

Hi @Gallatin 21V ,
It seems that your observation of all inbound requests to your Azure Linux Web App being logged on port 80, regardless of whether the requests were made via HTTP or HTTPS, could be due to how Azure handles incoming traffic. In Azure App Service, HTTP traffic is typically served on port 80, while HTTPS traffic is served on port 443. However, when HTTPS requests are made, they are often redirected to HTTP for logging purposes, which might explain why you see only port 80 in your logs.

This behavior could be by design, particularly if there are specific configurations or settings applied to your Linux Web App that differ from those of the Windows Web App. It is advisable to review the configuration settings of your Linux Web App to ensure that HTTPS is properly set up and that any necessary SSL certificates are correctly configured.

App Service networking features
App Service Environment networking

Hope this information is helpful, let me know if you have any further queries.
Gallatin 21V 186 Reputation points

2025-04-24T07:26:00.68+00:00

Hi @Bhargavi Naragani , thanks for your quick reply . But it might cloud not explian that when I request windows webapp, it can be record corrcetly. I request https , ports in logs is 443, requset http, ports in logs is 80. Is there any difference when log request for windows webapp and linux webapp?
Bhargavi Naragani 3,075 Reputation points Microsoft External Staff

2025-04-24T07:51:08.8+00:00

Hi @Gallatin 21V

All-incoming requests to your Azure Linux Web App are being logged with port 80, regardless of whether the requests were made using HTTP or HTTPS. This was confirmed through Application Insights logs and AppServiceHTTPLogs (Diagnostic Logs)

The same tests on an Azure Windows Web App do show correct ports, port 443 for HTTPS and port 80 for HTTP. So, this is a real and known behavior difference between Azure Linux and Windows Web Apps. It is not a bug, but rather by design due to how request routing and logging are handled in the underlying infrastructure of Azure App Service for Linux.

When you make an HTTPS request to an Azure App Service, Azure terminates TLS at the front-end load balancer. This means the load balancer decrypts the HTTPS request then forwards the request to the app over HTTP internally (i.e., on port 80). As a result, the app and logging layers (e.g., AppServiceHTTPLogs, Application Insights) only see port 80, not the original 443.

This behavior is specific to Azure App Service on Linux. In contrast, Windows App Services handle the logging stack differently, and the original client port (443) is preserved and visible in logs like AppServiceHTTPLogs.

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All inbound request port to Azure Linux Webapp is 80, not 443 in logs( in application insights & AppServiceHTTPLogs Table)

Your answer