nslookup – query DNS servers
nslookup queries DNS servers to look up hostnames and IP addresses.
Synopsis
nslookup [HOST] [SERVER]
Examples
Basic lookup
$ nslookup google.com
Server: 192.168.1.1
Address: 192.168.1.1#53
Non-authoritative answer:
Name: google.com
Address: 142.250.187.206
Reverse lookup (IP to name)
$ nslookup 8.8.8.8
Server: 192.168.1.1
Address: 192.168.1.1#53
Non-authoritative answer:
8.8.8.8.in-addr.arpa name = dns.google.
Use specific DNS server
$ nslookup google.com 8.8.8.8
$ nslookup google.com 1.1.1.1
Query specific record type
$ nslookup -type=mx gmail.com
$ nslookup -type=ns example.com
$ nslookup -type=txt example.com
Record Types
| Type | Description |
|---|---|
| A | IPv4 address |
| AAAA | IPv6 address |
| MX | Mail server |
| NS | Name server |
| TXT | Text record |
| CNAME | Canonical name |
| SOA | Start of authority |
dig: Better Alternative
dig provides cleaner, more detailed output:
$ dig google.com
$ dig +short google.com # Just the answer
$ dig MX gmail.com
Tips
- Use dig for scripting: Cleaner output
- Check multiple DNS servers: Compare results
- Reverse lookups: Use IP address as argument
- MX records: Important for email troubleshooting
