Troubleshooting Connectivity Issues between a Virtual Machine (VM) and an Azure Container App

In today’s cloud-centric world, ensuring seamless connectivity between various components is critical to maintaining efficient workflows and minimizing downtime. One common scenario is troubleshooting connectivity issues between virtual machines (VMs) and Azure container apps. This guide aims to provide a basic approach to identifying and resolving connectivity issues, covering key aspects such as ingress configuration, troubleshooting tools, and networking components. Following these steps will ensure that your VMs and Azure container apps can communicate effectively.

Troubleshooting connectivity issues between a virtual machine (VM) and an Azure container app can require several steps.

Here are some key steps to perform or check:

1. Reviewing Ingress Configuration
   

   script	explanation	act
   Requests to endpoints fail.	The container app endpoint is not responding to requests.	Reviewing Ingress Configuration

   Troubleshoot Azure Container Apps | Microsoft Learn

2. Check your DNS name Unique identifier>..azurecontainerapps.io or *. The container app environment correctly resolves to the static IP address 10.0.8.209.
   1. 

   2. Networking in Azure Container App Environments | Microsoft Learn
   3. Custom environment DNS suffix for Azure container apps | Microsoft Learn
3. Test connectivity between the VM and the container app using Psping or Test-NetConnections..
4. The result should show TcpTestSucceeded = True or PSping <Container app environment static IP>:
5. 
6. https://learn.microsoft.com/en-us/sysinternals/downloads/psping

7. NOTE: Tracert returns Timedout because there is no option to set the listening port (disable command usage)

   

8. You can also use curl -v <For container app environment static IP> connection. This command should return HTTP 404.
9. 

10. If the connection test fails,

    1. Make sure the destination port is correct and that the Azure Container App’s ingress settings are configured to allow traffic within the virtual network.
    2. 

    3. check NSGs associated with VMs and container apps allow traffic on required ports (e.g. HTTP/HTTPS).

    4. Check route table for forced tunneling traffic for NVA and cCheck if there are any firewall rules that might be blocking traffic to your container app.