nslookup Command Reference: Usage & CI Examples

nslookup queries DNS name servers for records.

nslookup is a widely available DNS lookup tool. It is less script-friendly than dig but is often present where dig is not, which makes it a useful fallback in minimal images.

Common flags and usage

nslookup <name>: resolve a hostname
nslookup <name> <server>: query a specific resolver
-type=MX / -type=TXT: query a record type
nslookup <ip>: reverse lookup
Output includes the answering server and address

Example

shell

nslookup api.example.com
nslookup -type=TXT example.com 8.8.8.8

In CI

Use nslookup as a quick resolution check when dig is unavailable. Its output is harder to parse than dig +short, so prefer dig for scripted assertions and keep nslookup for interactive debugging.

Key takeaways

nslookup resolves names and queries record types.
It is a fallback when dig is not installed.
dig +short is easier to parse for scripted checks.

Related guides

dig Command Reference: Flags, Usage & CI ExamplesReference for dig: +short, record types, @server, +trace, and a CI example that resolves a hostname to verify… getent Command Reference: Databases, Usage & CI ExamplesReference for getent: hosts, passwd, group, the NSS-aware lookup advantage, and a CI example that resolves a… ping Command Reference: Flags, Usage & CI ExamplesReference for ping: -c, -W, -i, the ICMP-blocked caveat, and a CI example that checks basic host reachability…