NSLOOKUP, DIG, and HOSTNAME Command-Line Tools (Video)

Flashcards cover key concepts and commands from NSLOOKUP, DIG, and HOSTNAME, including modes, record types (A, MX, CNAME), and related DNS concepts.

NSLOOKUP

Name Server Lookup; a command-line tool used to query DNS servers to map domain names to IP addresses and retrieve DNS records.

Non-interactive mode

NSLOOKUP mode in which you enter a domain on one line and receive a single set of results (no interactive shell).

Interactive mode

NSLOOKUP shell that allows multiple queries, changing the DNS server, and selecting different record types.

server (NSLOOKUP command)

NSLOOKUP command to specify which DNS server to use for lookups.

set q equals MX

NSLOOKUP command to set the query type to MX (mail exchange) records; commonly used in Windows syntax.

set type equals MX

NSLOOKUP command to set the query type to MX when using Linux/Unix/OSX; equivalent to set q equals MX in Windows.

MX record

Mail Exchange DNS records; designate mail servers for a domain and include a priority value (lower numbers = higher priority).

MX record priority

Priority value for MX records; lower numbers indicate higher priority and influence mail delivery order.

CNAME

Canonical Name record; creates an alias from one domain name to another domain name.

A record

Address record; maps a domain name to an IPv4 address.

DIG

DNS query tool available by default on Linux/Unix/OSX (Windows versions exist); queries DNS similarly to NSLOOKUP and returns DNS records (A by default).

dig -t MX

DIG command option to query for MX (mail exchange) records for a domain.

hostname command

Command used to display the host name portion of the system's full computer name.

FQDN

Fully Qualified Domain Name; the complete domain name that uniquely identifies a host within the DNS hierarchy.