NSLookup DNS Query Tool for iOS and iPhone

What is NSLookup?

The nslookup command queries DNS (Domain Name System) servers to translate domain names into IP addresses and vice versa. It is essential for diagnosing DNS resolution issues, verifying DNS propagation after changes, and understanding how domain names map to servers.

How to Use NSLookup on iOS

> nslookup apple.com

The command returns the IP addresses associated with the domain, along with the DNS server used for the query.

Why DNS Lookups Matter

DNS issues are among the most common causes of website downtime and connectivity problems. Being able to quickly verify DNS resolution from your iPhone allows you to diagnose issues in real-time — whether you are updating DNS records, migrating hosting providers, or troubleshooting why a site is unreachable.

Troubleshooting Tips

• Compare results from different DNS servers to check propagation
• Verify A, AAAA, and CNAME records are correct
• Use alongside flushdns to clear cached results