Skip to tutorial content
Rate module Not yet rated

DNS, Proxy and Network-Zone Considerations

4 min read
On this page

In this lesson, you will learn:

  • How a MID Server uses DNS
  • How to set up a proxy
  • How zones affect reach

🔁 Quick look back: Last time: Clusters, Load Balancing and Failover. You learned how MID Server clusters give load balancing or failover.

1 The Problem: The MID Server Can’t Reach snwr Through the Proxy

snwr-mid-aws-01 installed fine, but stayed Down. The cause:

  • SNWR sends internet traffic through a web proxy.
  • The MID Server wasn’t told about it.

🎯 The problem: The MID Server couldn’t reach the instance through the proxy.

👉 The fix: Set the proxy on the MID Server, and check DNS and zones for each one.

Cards: DNS, proxy, zones.
Figure 1. Network settings every MID Server needs.

2 DNS

The MID Server uses the host’s DNS servers. If the host resolves names wrongly, CIs get wrong names. You checked this in Client Prerequisites.

3 Proxy

Many companies send internet traffic through a proxy. The MID Server’s config file has settings for the proxy host, port and login if needed.

⚠️ Heads up: Don’t let the proxy inspect and change the MID Server’s HTTPS traffic unless it’s set up for it. It can break the connection.

4 Zones

  • A MID Server reaches other zones only through firewall rules.
  • Every cross-zone path should be in the port matrix.

5 Project Clear View: How We Implemented It

📍 Situation: snwr-mid-aws-01 stayed Down after install.

🧭 Decision: Find the cause and set the proxy.

🛠️ Steps we took:

  1. Read the MID agent log. It showed timeouts to snwr.
  2. Asked Kenji: AWS traffic goes through a proxy.
  3. Set the proxy host and port in the MID config, then restarted it.
  4. Checked DNS from the host.

✅ What we verified:

  • snwr-mid-aws-01 is Up and validated.
  • DNS lookups work from the VPC.

📁 Evidence: Proxy settings recorded in the runbook.

6 Quick recap

  • The MID Server uses the host’s DNS.
  • Set the proxy in the MID config if the company uses one.
  • Proxies that inspect HTTPS can break the connection.
  • Cross-zone paths need firewall rules.

7 Check yourself

Think of your answer first. Then tap to check.

1 Why was snwr-mid-aws-01 Down? Show answer

It wasn’t told about SNWR’s web proxy.

2 Where are proxy settings for a MID Server? Show answer

In the MID Server’s config file.

3 Which DNS does a MID Server use? Show answer

The host’s DNS servers.

Nice work! SNWR’s MID Servers reach what they need. 🎉
Next up: MID Server Sizing, Threads and Performance

Was this lesson helpful?

Have a question or doubt?

Ask here and get help from instructors and fellow learners.

0 / 300

Only logged-in learners can post.