DNS Lookup Tool

Query and understand DNS records for any domain. Explains record types, checks propagation, verifies configuration, and troubleshoots common DNS issues.

Usage

Provide a domain name and what you want to check. The tool explains how to query DNS records, interpret results, and diagnose common configuration issues.

Parameters

• Domain: The domain to query
• Record type: A, AAAA, CNAME, MX, TXT, NS, SOA, or All
• Task: Lookup, Propagation check, Configuration verification, or Troubleshooting
• Context: New domain setup, Migration, Email configuration, or SSL/CDN setup

Examples

1. Domain Migration Check: Verify DNS configuration after migrating to a new host — check A records point to new IP, MX records are preserved, and SPF/DKIM TXT records are intact.

1. Email Deliverability: Check all email-related DNS records — MX priority, SPF (TXT), DKIM (CNAME/TXT), and DMARC policy, with specific fixes for missing or incorrect records.

1. CDN/Cloudflare Setup: Verify DNS configuration for Cloudflare — proxied vs. DNS-only records, proper CNAME flattening, and SSL certificate compatibility.

1. Subdomain Routing: Configure DNS for multiple services on subdomains — A records for servers, CNAME for SaaS services, and TXT verification records for third-party tools.

Guidelines

• Record types are explained with purpose: A (IPv4), AAAA (IPv6), CNAME (alias), MX (mail), TXT (verification/SPF)
• dig command syntax covers basic lookups, specific record types, and querying specific nameservers
• TTL (Time To Live) is explained for understanding propagation delays after changes
• Propagation checking uses multiple DNS servers (Google 8.8.8.8, Cloudflare 1.1.1.1, authoritative NS)
• Common misconfigurations are identified: CNAME at apex, conflicting A/CNAME, missing MX
• Email authentication records (SPF, DKIM, DMARC) are explained with correct syntax
• DNSSEC validation status is checked and explained
• Reverse DNS (PTR) records are verified for email servers and IP reputation
• DNS caching at multiple levels (browser, OS, ISP) is explained for troubleshooting "still see old site"
• Security implications of DNS are addressed: zone transfer protection, CAA records for SSL