cybersec+ section 5

Term 1: Why do security professionals often prefer the Command-Line Interface (CLI) over a Graphical User Interface (GUI)?
Definition 1: The CLI provides deeper, scriptable, and automated control. GUIs only expose a limited set of options determined by the developer.
(Exam Domain 1.0 General Security Concepts)
Term 2: What is the difference between a shell and a terminal?
Definition 2: A terminal is the program that provides the window and interface. The shell is the command interpreter that runs within the terminal and executes commands (e.g., PowerShell, bash).
Term 3: What are the two primary command-line shells on modern Windows systems?
Definition 3: * cmd.exe (legacy Command Prompt)

• PowerShell (modern, object-oriented)
  Term 4: What is the most common shell found on Linux and macOS systems?
  Definition 4: bash (Bourne-Again Shell). It is a POSIX-compliant shell.
  Term 5: What is the industry standard for secure, authenticated, and encrypted remote CLI access?
  Definition 5: Secure Shell (SSH). It is a critical secure protocol to know versus insecure methods like Telnet.
  (Exam Domain 4.2 Implement secure network services and protocols)
  Term 6: What is the primary purpose of the ping command?
  Definition 6: To test Layer 3 (IP) network connectivity and verify that the remote host's firewall allows ICMP traffic.
  Term 7: How does the default behavior of ping differ between Windows and Linux/macOS?
  Definition 7: * Windows: Sends 4 ICMP echo requests and stops.

• Linux/macOS: Pings continuously until stopped (Ctrl-C).
  (This is an exam tip for identifying the OS in a screenshot.)
  Term 8: How can you use ping to test DNS resolution?
  Definition 8: Ping a Fully Qualified Domain Name (FQDN) like ping www.google.com. The first line of the output will show the name being resolved to an IP address, which confirms DNS is working, even if the pings themselves fail.
  Term 9: What Windows command displays the IPv4/IPv6 address, subnet mask, and default gateway for all network adapters?
  Definition 9: ipconfig
  Term 10: Which Windows command reveals the physical (MAC) address and DHCP lease information?
  Definition 10: ipconfig /all
  (A common exam question is "Which command reveals the physical address?")
  Term 11: A Windows machine has an outdated DNS record and cannot browse a site that recently changed its IP. Which command would clear the local DNS resolver cache?
  Definition 11: ipconfig /flushdns
  Term 12: You suspect a duplicate IP address on the network. Which two ipconfig commands can you run in sequence to get a fresh IP lease from the DHCP server?
  Definition 12: * ipconfig /release

• ipconfig /renew
  Term 13: What is the legacy command on Linux for viewing network configuration, and what modern command is replacing it?
  Definition 13: * Legacy: ifconfig (still relevant for the exam)

• Modern: ip (e.g., ip addr)
  Term 14: An exam question shows a screenshot of ping -t 8.8.8.8 running endlessly. Which operating system is depicted?
  Definition 14: Windows. The -t switch creates a continuous ping on Windows. Linux/macOS ping continuously by default without a switch.
  Term 15: You can resolve a hostname, but your pings result in "Request timed out." What is the most likely cause?
  Definition 15: A firewall is blocking ICMP packets. DNS resolution proves basic connectivity and name services are working, pointing the blame to a security filter.
  Term 16: Which two pieces of information from ipconfig are essential to confirm that your host can route traffic to another subnet?
  Definition 16: * IPv4 Address (your address)

• Default Gateway (the router's address)