Summary

Here's a summary of the website content regarding the 502 Bad Gateway error related to Microsoft Azure Application Gateway v2:

The 502 Bad Gateway error indicates that the Application Gateway itself encountered an error while trying to communicate with the backend server(s) it’s routing traffic to. This is a very common error and often points to issues within the backend pool – not the Application Gateway itself.

Key Causes:

* Backend Server Issues: The most frequent cause is that one or more of the servers in your backend pool are unavailable, overloaded, experiencing errors, or are down.
* Network Connectivity Problems: Problems with the network connection between the Application Gateway and the backend servers. This could include firewall issues, DNS problems, or routing misconfigurations.
* Application Errors in Backend Servers: Bugs or errors within the applications running on the backend servers themselves can lead to them failing to respond correctly, causing the gateway to return a 502.
* Application Gateway Configuration Issues: Rarely, misconfigurations within the Application Gateway's settings (e.g., timeout settings, health probe misconfigurations) can contribute.
* Load Balancer Issues: Problems with the underlying load balancer that the backend servers are sitting behind could be a contributing factor.

Troubleshooting Steps:

* Check Backend Server Health: Verify the status of all backend servers in your pool. Ensure they are running and responding to requests.
* Examine Application Gateway Logs: The Application Gateway logs will provide detailed information about the error, including timestamps and potential error codes.
* Review Network Connectivity: Test network connectivity between the Application Gateway and the backend servers.
* Check Application Logs: Analyze the logs of the backend applications for any errors.
* Verify Application Gateway Configuration: Double-check your Application Gateway's settings, particularly health probes, timeouts, and SSL settings.

In short, a 502 Bad Gateway error almost always indicates a problem upstream – typically within your backend servers or the network connection between them and the Application Gateway.

Title

502 Bad Gateway

Description

502 Bad Gateway

Keywords

gateway, azure, application

NS Lookup

A 20.105.248.122

Dates

Created 2026-03-14

Updated 2026-03-15

Summarized 2026-03-17