The dig (Domain Information Groper) command is a standard and powerful command-line tool in Linux used for interrogating Domain Name System (DNS) servers. Its primary purpose is to perform DNS lookups and return detailed information from the name server, including A records, MX records, and other DNS data. For an administrator troubleshooting DNS resolution, dig is the most appropriate and direct tool as it provides comprehensive output specifically tailored for diagnosing DNS issues.

A. traceroute: This command is used to trace the network path (route) packets take to a destination, not to test DNS resolution directly.

B. netstat: This command displays network connections, routing tables, and interface statistics; it does not perform DNS queries for troubleshooting.

D. ifconfig: This command is used to view and configure network interface parameters, such as IP addresses, and is not used for DNS lookups.

1. University Courseware:

MIT OpenCourseWare

6.033 Computer System Engineering

Spring 2018

Recitation 10: Naming. The notes explicitly introduce dig as the tool for querying the DNS. "To query the DNS

we can use the dig command." (Section 2

Paragraph 1).

Available at: https://ocw.mit.edu/courses/6-033-computer-system-engineering-spring-2018/resources/mit6033s18rec10/

2. Official Vendor Documentation:

Red Hat Enterprise Linux 8 Documentation

Configuring and managing networking

Chapter 36. Analyzing network traffic. The documentation lists dig as a primary utility for DNS troubleshooting. "The dig utility sends a DNS query to a name server and displays the result." (Section 36.2.1. Querying DNS records using dig).

Available at: https://access.redhat.com/documentation/en-us/redhatenterpriselinux/8/html/configuringandmanagingnetworking/analyzing-network-trafficconfiguring-and-managing-networking

3. Official Linux Documentation (Man Page):

The Linux man-pages project

dig(1). The official manual page describes the tool's function. "dig (domain information groper) is a flexible tool for interrogating DNS name servers. It performs DNS lookups and displays the answers that are returned from the name server(s) that were queried." (NAME section).

Available at: https://man7.org/linux/man-pages/man1/dig.1.html