When working with Azure DevOps proxy Support in enterprise environments, it's common to run self-hosted agents behind a corporate proxy. These proxies often restrict outbound internet access for security reasons. To ensure your pipelines run smoothly, it’s critical to configure proxy settings correctly on your self-hosted agents. In this post, we’ll explain how to set up proxy support for Azure DevOps self-hosted agents and what you need to watch out for during configuration—especially in interview scenarios where understanding infrastructure bottlenecks is key.

Why Use a Self-Hosted Agent?

Self-hosted agents provide more control over the build and deployment environment. They are particularly useful when:

• You require custom tools or dependencies.

• You're operating within a secure or isolated network.

• Your organization wants to optimize performance and reduce cost compared to Microsoft-hosted agents.

Common Proxy Challenges

In restricted environments, self-hosted agents must pass through an HTTP or HTTPS proxy to reach Azure DevOps services (like dev.azure.com or *.visualstudio.com). Without proper proxy configuration, you’ll encounter errors such as:

• "Unable to connect to Azure DevOps services."

• "TLS/SSL handshake failed."

• "No internet access detected."

Configuring Proxy for Self-Hosted Agent

Here’s how you can configure a proxy for Azure DevOps self-hosted agents:

Step 1: Install the Agent

Download the agent from Azure DevOps > Organization Settings > Agent Pools. Extract the zip file and run the configuration script:

This will prompt for connection info and authentication method.

Step 2: Set Proxy Environment Variables

Before configuring the agent, set the following environment variables in the command prompt or script where the agent runs:

For Linux:

If authentication is required, use:

⚠️ Note: Avoid exposing credentials in plaintext; consider using credential managers or system-wide secure storage.

Step 3: Whitelist Required URLs

Ensure your proxy or firewall allows outbound traffic to:

• https://dev.azure.com

• https://*.visualstudio.com

Refer to Microsoft’s official documentation for the complete list of IPs and URLs.

Step 4: Run the Agent

After configuration, start the agent:

Or on Windows:

Final Thoughts

Setting up a self-hosted agent behind a proxy requires attention to detail, especially around network access and security policies. For DevOps interviews, be prepared to explain proxy setups, common errors, and how you'd troubleshoot connection issues.

Understanding these configurations demonstrates practical networking knowledge and real-world cloud DevOps experience.