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AP Networking

Tools of network analysts: using the CLI

Many network devices ship without a graphical interface — the CLI is their only configuration tool. Learning to navigate file systems, run commands, and transfer files securely using the command line is an essential skill for any network analyst.

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What this topic covers

  • › 4.3.A — CLI vs. GUI; navigating Linux and Windows file systems with commands
  • › 4.3.B — SSH and SFTP for secure remote connections and file transfers

Why CLI over GUI?

CLIs allow simplified automation and repetition of tasks. They take up less storage space and use less processing power than GUIs, leaving more resources available for the device's actual tasks. Many routers, switches, and servers have no GUI at all — the CLI is the only way to configure them.

File system paths (4.3.A)

Understanding how paths work in Linux and Windows is fundamental to navigating the CLI effectively.

Linux paths

  • › Paths start from the root directory: /
  • › Directories are separated by forward slashes: /home/user/Desktop
  • › Tilde (~) refers to the current user's home directory
  • › Dollar sign ($) at the end of the prompt indicates the shell is ready for input

user@hostname /home/user/Desktop $

# ready for input in Desktop directory

user@hostname ~ $

# ready for input in home directory

Windows Command Prompt paths

  • › Paths start with a drive letter: C:\
  • › Directories are separated by backslashes: C:\Users\username\Desktop
  • › Right-angle bracket (>) at the end of the path indicates the shell is ready for input

C:\Users\admin\Desktop>

REM ready for input in Desktop directory

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Command syntax

All CLI commands follow a standard pattern: command → options → arguments

Command

The program to execute: ls, cd, ping

Options (flags/switches)

Modify behavior, denoted with a dash: -a, -r. Optional.

Arguments

Specify the target: a file name or directory path. Some commands require them; others don't.

ls # list current directory (no options or arguments)

ls -a # list current directory including hidden files

ls user1 # list user1 directory, excluding hidden files

ls -a user1 # list user1 directory including hidden files

Navigation commands

Command OS Purpose
cd subdirectory Mac/Linux/Windows Move into a subdirectory of the current directory
cd .. Mac/Linux/Windows Move to the parent directory (one level up toward root)
cd ~ Mac/Linux Move to the current user's home directory
cd / Mac/Linux Move to the root directory
ls Mac/Linux List contents of the current (or specified) directory
dir Windows View contents of the current directory
pwd Mac/Linux Print the current working directory path
help / man Both Get help on a command — help for overview, man for detailed documentation
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Secure file transfer with SSH and SFTP (4.3.B)

SSH — Secure Shell

SSH is a protocol for securing remote CLI connections. It encrypts all data exchanged between the user and the remote device — including login credentials. SSH uses port 22.

SFTP — Secure File Transfer Protocol

SFTP runs over SSH to transfer files securely between devices. Because it uses SSH, all data and credentials are encrypted. SFTP also uses port 22.

# connect to remote host via SFTP

sftp panda@192.168.1.15

# nothing appears while typing password (security feature)

Inside an SFTP session

Navigate the remote device

  • ls — list contents of the current remote directory
  • cd — change the remote directory
  • pwd — view the current remote working directory

Transfer files

  • get filename — download a file from the remote device to the local device
  • put filename — upload a file from the local device to the remote device