Description
The dns-debugger script performs in-depth DNS resolution tests for specified domain names. Unlike basic nslookup or dig checks, it traces the full query path, from local resolver to authoritative server, to identify delays, failures, or unexpected resolutions. It captures not only whether a domain resolves, but how long each step takes, what TTL values are returned, and which resolver was involved.
This script is extremely useful for debugging domain-related connectivity problems, whether caused by misconfigured DNS servers, hijacking by captive portals, ISP-based DNS filtering, or slow resolution times.
It supports testing against system-resolved DNS servers as well as specified alternatives like Google DNS (8.8.8.8), Cloudflare (1.1.1.1), or internal enterprise resolvers. It may also flag mismatched DNS results across servers, which is often a sign of poisoning or regional discrepancies.
In security contexts, dns-debugger is often used to verify DNS leak protection on VPN setups, or to investigate if malicious domains are being blocked or redirected. It’s also helpful in CDN troubleshooting, when domains are expected to resolve to the nearest geographic node but don’t.
Mubarak –
“This dns-debugger is an incredibly helpful tool for understanding and troubleshooting DNS issues. The step-by-step resolution testing, combined with the ability to check various servers and detect slow queries, makes it invaluable for diagnosing potential problems. I especially appreciate the custom server support and the clear presentation of response times and TTL values. It’s a must-have for anyone dealing with DNS configuration or security.”
Folasade –
“This is an absolutely fantastic tool for anyone dealing with DNS issues. It’s incredibly helpful for understanding exactly what’s happening with domain name resolution and pinpointing bottlenecks. The step-by-step testing and the ability to check different servers make troubleshooting DNS problems much easier and faster. A must-have utility for network admins and developers alike!”
Festus –
“This tool is incredibly helpful for understanding DNS resolution issues. It breaks down the entire process in a clear, step-by-step way, making it easy to pinpoint the source of problems. The ability to test with custom DNS servers is a fantastic feature, and the insights into response times and TTL values are invaluable for diagnosing slow or suspicious DNS activity. A must-have for anyone working with networking or security.”
Faiza –
“This dns-debugger file is incredibly helpful for understanding DNS resolution. I was able to quickly pinpoint a slow DNS query that was impacting my website’s performance. The step-by-step testing and the ability to check different servers, along with clear response times, made diagnosing the issue straightforward. It’s a fantastic tool for anyone wanting to delve into their DNS setup and troubleshoot problems.”