nslookup Cheatsheet
Quick reference for querying DNS records and checking name resolution with nslookup
The nslookup command queries DNS servers for domain and reverse lookup records. This cheatsheet covers quick host lookups, record type queries, reverse DNS, interactive mode, and a few practical troubleshooting checks.
Basic Syntax
Core nslookup command forms.
| Command | Description |
|---|---|
nslookup example.com | Look up a domain using the default resolver |
nslookup example.com 8.8.8.8 | Query a specific DNS server |
nslookup -type=mx example.com | Query a specific record type |
nslookup 192.0.2.1 | Run a reverse DNS lookup |
nslookup | Start interactive mode |
Common Lookups
Quick checks for hostnames and addresses.
| Command | Description |
|---|---|
nslookup example.com | Look up A and AAAA records using the default resolver |
nslookup www.example.com | Check a hostname or subdomain |
nslookup localhost | Verify local name resolution |
nslookup 127.0.0.1 | Reverse lookup for the local loopback address |
nslookup 192.0.2.1 | Reverse lookup for a public IP address |
Record Types
Use -type to query specific DNS records.
| Command | Description |
|---|---|
nslookup -type=a example.com | Query IPv4 address records |
nslookup -type=aaaa example.com | Query IPv6 address records |
nslookup -type=mx example.com | Query mail exchanger records |
nslookup -type=ns example.com | Query authoritative name servers |
nslookup -type=txt example.com | Query TXT records |
nslookup -type=soa example.com | Query the SOA record |
nslookup -type=cname www.example.com | Check whether a hostname is an alias |
nslookup -type=any example.com | Run an ANY query |
Specific DNS Servers
Compare answers from different resolvers.
| Command | Description |
|---|---|
nslookup example.com 8.8.8.8 | Query Google Public DNS |
nslookup example.com 1.1.1.1 | Query Cloudflare DNS |
nslookup example.com 9.9.9.9 | Query Quad9 |
nslookup -type=mx example.com 8.8.8.8 | Query MX records from a specific resolver |
nslookup -type=txt example.com 1.1.1.1 | Compare TXT answers between resolvers |
Interactive Mode
Run multiple queries in one session.
| Command | Description |
|---|---|
nslookup | Open interactive mode |
set type=mx | Switch the active query type to MX |
set type=txt | Switch the active query type to TXT |
server 8.8.8.8 | Change the active DNS server |
example.com | Query a domain after entering interactive mode |
exit | Leave the interactive session |
Troubleshooting
Quick checks for common nslookup errors.
| Issue | Check |
|---|---|
NXDOMAIN | Verify the domain name and make sure it exists |
SERVFAIL | Try another resolver such as 8.8.8.8 or 1.1.1.1 |
Connection timed out; no servers could be reached | Check network access and verify /etc/resolv.conf |
Non-authoritative answer | Normal cached response from a resolver |
No answer | The queried record type is not set for that name |
Related Guides
Use these guides for fuller DNS troubleshooting workflows.
| Guide | Description |
|---|---|
| nslookup Command in Linux | Full nslookup guide with practical examples |
| How to Use the dig Command to Query DNS in Linux | Detailed dig guide for deeper DNS debugging |
| dig Cheatsheet | Quick dig command reference |
| ping Cheatsheet | Quick connectivity checks before DNS troubleshooting |
| IP command cheatsheet | Inspect interfaces, addresses, and routes |
| curl Cheatsheet | Test HTTP reachability after DNS resolution succeeds |