nslookup and dig for DNS in Linux CLI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the primary purpose of the nslookup command?

nslookup is used to query DNS servers to find the IP address associated with a domain name or vice versa.

intermediate

How does dig differ from nslookup in DNS queries?

dig provides more detailed and flexible DNS query information and is preferred for troubleshooting DNS issues, while nslookup is simpler and more basic.

beginner

What does the command nslookup google.com do?

It queries the default DNS server to find the IP address(es) for google.com.

intermediate

What is the purpose of the +short option in dig?

The +short option shows only the answer section of the DNS query, making the output concise and easy to read.

beginner

Which command would you use to find the mail servers (MX records) for a domain?

You can use either nslookup -query=mx domain.com or dig mx domain.com to find mail servers for a domain.

What does the dig command primarily do?

A Check disk usage

B Display network interface details

C Query DNS servers for domain information

D Monitor system processes

dig is used to query DNS servers to get information about domain names.

Which option with dig gives a brief output showing only the IP address?

A +short

B +trace

C +all

D +stats

The +short option shows only the answer section, making output brief.

How do you specify the DNS record type in nslookup?

A Using the <code>-type</code> or <code>-query</code> option

B Using the <code>-record</code> option

C Using the <code>-dns</code> option

D You cannot specify record type in nslookup

You specify record type with -type= or -query= in nslookup.

Which command would you use to find the authoritative name servers for a domain?

A nslookup domain.com

B nslookup -query=mx domain.com

C dig a domain.com

D dig ns domain.com

dig ns domain.com queries for name server (NS) records, showing authoritative servers.

If nslookup returns 'server can't find domain.com: NXDOMAIN', what does it mean?

A The DNS server is down

B The domain does not exist

C The IP address is blocked

D The query timed out

NXDOMAIN means the domain name does not exist in DNS.

Explain how you would use nslookup and dig to troubleshoot a website that is not loading.

Think about checking if the domain name resolves and what DNS info you can get.

Describe the difference in output detail between nslookup and dig.

Consider which tool is better for quick checks vs deep troubleshooting.