Linux+ Linux+ Networking Services and Protocols

Question 1

Which command generates an SSH key pair on a Linux system?

Accepted Answer

ssh-keygen

Answer

ssh-keygen creates RSA, ECDSA, or Ed25519 key pairs used for SSH public-key authentication.

Question 2

Which file on an SSH server is the primary configuration file for the SSH daemon?

Accepted Answer

/etc/ssh/sshd_config

Answer

/etc/ssh/sshd_config is the main configuration file for the SSH daemon (sshd) and controls server-side behavior.

Question 3

Which DNS record type maps a hostname to an IPv4 address?

Accepted Answer

A

Answer

An A record maps a hostname to an IPv4 address; AAAA records are used for IPv6 addresses.

Question 4

Which command provides the most detailed DNS query output, including response time and authoritative server information?

Accepted Answer

dig

Answer

dig (Domain Information Groper) provides verbose DNS query output including query time, server used, and full answer sections.

Question 5

What TCP port does SSH use by default?

Accepted Answer

22

Answer

SSH uses TCP port 22 by default for establishing encrypted remote connections.

Linux Practice Test