Resolve domain names to server IP addresses (A/AAAA records)
DNS (Domain Name System) is the internet's "phone book" — it translates human-readable domain names (like google.com) into machine-readable IP addresses (like 142.250.80.46). A DNS lookup tool helps you diagnose domain resolution issues and verify that DNS configurations have taken effect.
| Type | Purpose | Example |
|---|---|---|
| A | Domain → IPv4 address | 93.184.216.34 |
| AAAA | Domain → IPv6 address | 2606:2800:220:1::248 |
| CNAME | Alias pointing to another domain | www.example.com → example.com |
| MX | Mail server address | mail.google.com (priority 10) |
| TXT | Text records (SPF, DKIM, etc.) | v=spf1 include:_spf.google.com |
| NS | Name servers | ns1.example.com |
TTL (Time To Live): How long a DNS record is cached. Shorter TTL = faster propagation of changes; longer TTL = faster lookups (higher cache hit rate).
example.com — no protocol prefix needed)DNS changes have propagation delays. Cached records at each resolver level won't be refreshed until the old TTL expires. Global propagation typically takes minutes to 48 hours. Best practice: lower TTL to 300 seconds (5 minutes) before making changes, then increase it again after propagation.
An A record maps a domain directly to an IP address; a CNAME maps a domain to another domain name (alias). CNAME's advantage is that if the target IP changes, you don't need to update your record. However, the zone apex (example.com) cannot have a CNAME — only A records (or vendor-specific alternatives like ALIAS/ANAME).
Query the same domain using different DNS resolvers (e.g., Google 8.8.8.8, Cloudflare 1.1.1.1). If results differ, DNS hijacking or cache poisoning may be occurring. Compare against the authoritative NS server's response to confirm the legitimate record.