dig

DNS Lookup utility.

• Lookup the IP(s) associated with a hostname (A records):

dig +short {{hostname.com}}

• Lookup the mail server associated with a given domain name (MX record):

dig +short {{hostname.com}} MX

• Specify an alternate DNS server to query (8.8.8.8 is google's public DNS):

dig @8.8.8.8 {{hostname.com}}

• Perform a reverse DNS lookup on an IP address (PTR record):

dig -x 8.8.8.8

• Find authoritative name servers for the zone and display SOA records:

dig +nssearch {{hostname.com}}