nslookup Command Examples: 15 Real-World DNS Queries

If you build websites, run mail servers, or troubleshoot DNS, nslookup is the fastest tool for a quick answer. This guide walks through 15 real-world queries you'll actually use — no fluff, just commands and what the output means.

Table of Contents

• What nslookup is
• Basic syntax
• Example 1 — A record
• Example 2 — AAAA (IPv6)
• Example 3 — MX record
• Example 4 — TXT record
• Example 5 — CNAME
• Example 6 — NS (name servers)
• Example 7 — SOA
• Example 8 — Reverse DNS (PTR)
• Example 9 — Query a specific DNS server
• Example 10 — Interactive mode
• Example 11 — Set timeout and retries
• Example 12 — Query via TCP instead of UDP
• Example 13 — Debug mode
• Example 14 — Non-authoritative vs authoritative
• Example 15 — Batch queries with a script
• Common mistakes and troubleshooting
• FAQ

What nslookup Is

nslookup ('name server lookup') is a command-line utility that queries DNS servers directly. It's built into Windows, macOS and Linux. Every network engineer, sysadmin, and web developer needs it in their muscle memory.

Basic Syntax

nslookup [option] name [server]. If you don't specify a server, nslookup uses whatever DNS your OS is configured to use.

Example 1 — A Record

nslookup digimetricshub.com — returns the IPv4 address(es) mapped to the domain. This is the default record type.

Example 2 — AAAA (IPv6)

nslookup -type=AAAA cloudflare.com — returns the IPv6 address(es). Modern sites publish both A and AAAA.

Example 3 — MX Record

nslookup -type=MX gmail.com — returns the mail exchanger hosts and their priority values. Lower priority number = higher preference.

Example 4 — TXT Record

nslookup -type=TXT google.com — returns text records including SPF, DKIM, DMARC, and domain-verification strings for Google, Facebook, Microsoft 365 and so on.

Example 5 — CNAME

nslookup -type=CNAME www.github.com — CNAME (canonical name) points one name at another. Useful for verifying that www.example.com correctly forwards to example.com or a CDN.

Example 6 — NS (Name Servers)

nslookup -type=NS wikipedia.org — lists the authoritative name servers for the zone. If you changed hosts, this confirms whether the new NS records have propagated.

Example 7 — SOA

nslookup -type=SOA digimetricshub.com — returns the Start of Authority record with the primary NS, responsible email, and the zone's serial number. When the serial number changes, secondaries know to pull an update.

Example 8 — Reverse DNS (PTR)

nslookup 8.8.8.8 — nslookup detects that you passed an IP and automatically queries the reverse zone (in-addr.arpa) for a PTR record. Result: dns.google. See our dedicated guide for the full story.

Example 9 — Query a Specific DNS Server

nslookup digimetricshub.com 1.1.1.1 — forces the query at Cloudflare's public resolver, bypassing your OS setting. Great for testing whether an issue is your resolver or the actual record.

Example 10 — Interactive Mode

Just run nslookup with no arguments. You get a > prompt where you can type commands like set type=MX, then a domain, then another. Type exit to leave.

Example 11 — Set Timeout and Retries

nslookup -timeout=5 -retry=2 digimetricshub.com — useful on flaky links where the default single-try timeout produces false NXDOMAIN answers.

Example 12 — Query via TCP Instead of UDP

nslookup -vc digimetricshub.com forces TCP. Useful when large DNSSEC-signed answers get truncated over UDP.

Example 13 — Debug Mode

nslookup -debug digimetricshub.com prints the raw DNS packets, showing you the query flags, opcode and answer sections. Educational for anyone learning DNS internals.

Example 14 — Non-authoritative vs Authoritative

If the output starts with 'Non-authoritative answer:' the resolver served it from cache. To force an authoritative answer, query the name server directly: nslookup digimetricshub.com ns1.example.com.

Example 15 — Batch Queries with a Script

On Linux/macOS: for d in google.com bing.com duckduckgo.com; do nslookup -type=MX $d; done — runs the same query type against multiple domains. On Windows, use a .bat file with FOR loops.

Common Mistakes

• Forgetting -type= and getting the default A record when you wanted MX or TXT.
• Trusting a 'Non-authoritative' answer during migrations — always query the authoritative NS.
• Assuming ANY-type queries still work — many resolvers refuse them per RFC 8482.
• Running nslookup from behind a corporate proxy that intercepts DNS.
• Reading 'server can't find' as 'site is down' when it usually means wrong record type.

Troubleshooting

1. If every query fails: your resolver is unreachable. Try nslookup digimetricshub.com 1.1.1.1.
2. If one specific domain fails: check DNS Lookup online to confirm the record exists.
3. If MX/TXT looks wrong after a change: DNS is cached — wait for TTL or flush your resolver.
4. If you get ADDITIONAL SECTION but no ANSWER: try TCP with -vc.

Security Best Practices

• Don't rely solely on nslookup for security-sensitive checks — combine with dig +dnssec and a DNS Lookup tool.
• Query multiple public resolvers (1.1.1.1, 8.8.8.8, 9.9.9.9) to detect DNS hijacking on your network.
• Prefer DoH/DoT resolvers in production so answers can't be tampered with in transit.