nslookup(1)
Query DNS servers to resolve hostnames or IP addresses.
Synopsis
nslookup [OPTION] [NAME] [SERVER]Description
nslookup is an interactive and non-interactive DNS lookup utility. It sends queries to DNS servers to resolve hostnames to IP addresses and vice versa. nslookup operates in two modes: interactive (when run without arguments) and non-interactive (when given a hostname or IP).
The command can query specific DNS servers, perform reverse lookups, and retrieve various DNS record types (A, MX, NS, CNAME, etc.). Modern systems often prefer dig for scripting and host for simple lookups, but nslookup remains widely used for interactive DNS troubleshooting.
Common options
| Flag | What it does |
|---|---|
-type=TYPE | Query specific DNS record type (A, AAAA, MX, NS, CNAME, SOA, TXT, etc.) |
-query=TYPE | Alternative syntax for specifying record type to query |
-x | Perform reverse DNS lookup (IP to hostname) |
server SERVER | Set the default server to query (used in interactive mode) |
-timeout=SECONDS | Set query timeout in seconds |
-retry=NUMBER | Set number of retries for failed queries |
set all | In interactive mode, display all settings and options |
set debug | Enable debug output to see full DNS response details |
Examples
Resolve example.com to its IP address using default DNS server
nslookup example.comResolve example.com using Google's public DNS server (8.8.8.8)
nslookup example.com 8.8.8.8Query mail exchange (MX) records for example.com
nslookup -type=MX example.comQuery nameserver (NS) records for example.com's domain
nslookup -type=NS example.comPerform reverse lookup to find hostname associated with IP 192.0.2.1
nslookup -x 192.0.2.1Query TXT records for example.com (often used for SPF, DKIM checks)
nslookup -type=TXT example.comEnter interactive mode; type 'exit' to quit, use 'help' for commands
nslookupQuery CNAME (canonical name) records to find aliased hostnames
nslookup -type=CNAME www.example.com