Container DNS redundancy

What this Scenario does

This Scenario blocks DNS traffic within your containers, simulating a primary DNS provider failure. This tests whether your container DNS configuration correctly falls back to secondary DNS servers, an especially important consideration since containers often rely on the host's or orchestrator's DNS resolution.

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Why run this Scenario?

DNS can fail in many ways, including:

• Failures in nameservers and/or recursive resolvers, causing DNS queries to time out or return errors.
• Network saturation (or a DDoS attack) slowing down DNS queries or causing them to drop.
• Misconfigured Quality of Service (QoS) rules, causing the network to de-prioritize DNS traffic.

Running this Scenario can help:

• Verify that container-level DNS configuration supports failover to secondary providers.
• Validate that service discovery mechanisms continue working when primary DNS fails.
• Identify containers that rely on specific DNS providers without fallback configuration.
• Ensure that DNS failures don't cascade into service discovery outages across your containerized applications.

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Expected outcome

If the primary DNS provider fails, containerized services continue resolving DNS queries through secondary providers with no interruption.