Command Line Interface Project

In this project we learn various commands that help us when navigating through the terminal. In networking, the terminal is used for easy access connection to a router in order to configure a certain network.

Tree Diagrams
Key Linux Commands
House Activity
- Download Phase
- Navigating the House
Trouble Shooting Network Issues
Reflection

Tree Diagrams

Root Directory

└──HomeFolder 
├──Documents
├──Photos├── Essay.docx         
└──Music └── Gatsby.jpg

In Map the Maze part 1 we created tree diagrams to visualize directories in computers. My example directory shows the Root Directory which is always listed first. Next is typically user folders or home folders. Finnaly I created files and nested directories.

Key Linux Commands

Command	Description	Example Usage
`pwd`	Print Working Directory – shows your current location in the filesystem.	`pwd`
`cd`	Change Directory – navigate between folders.	`cd ~/DirectoryName` `cd ..`
`ls`	List files and folders in the current directory.	`ls` `ls -a`
`mkdir`	Make Directory – create a new folder.	`mkdir new_folder`
`touch`	Create a new file.	`touch file.txt`
`cat`	Display the contents of a file.	`cat file.txt`
`echo`	Print text or add content to a file.	`echo "Test 1" > file.txt`
`nano`	Edit files in the terminal.	`nano file.txt`

These images provide multiple examples of these commands being used.

House Activity

This activity was created in a Github repository. The repository was called house and it contained other folders that were the different rooms in the house. Different rooms contained files, hidden files, etc that were all clues to completing the activity.

To begin this activity first we had to download the map of the house aka the Github repository.

Download Phase

Following the insturctions provided by our teacher. First updating by running “sudo apt update.” Next sudo apt install -y git in order to be able to use the git commands in the VM terminal. Then changing directories to Documents followed by cloning the repository in Documents. “cd ~/Documents … clone https://github.com/thewangclass/CK-Building-Content-Knowledge-Workshop.git.” Finnaly after moving to the new directory by using “cd CK-Building-Content-Knowledge-Workshop.git.” and using “git pull” to make sure I had the most updated version. Originally when trying to install the github commands I recieved an error message. In order to fix this problem my teacher and I had to run the sudo nano /etc/systemd/resolved.conf command to open up the nano control. Following that we navigated to the DNS server and removed the # from the name and set it = to 8.8.8.8. Finnaly we restarted the system by running the sudo systemctl restart systemd-resolved.

Navigating the House

The first thing I had to do was rename the directories for the activity so that I could navigate easier. Task one was to enter the friends house. I did this by using “cd ~/Documents/House/Activity/house”. I listed all the folders in one command in order to be efficient and not have to type out a seperate command line for each folder. The next task was to see what is around the house. Using the “ls” command I found directories labled “bedroom1, bedroom2, garage, kitchen, main_entrance”. Next I had to enter the main_entrance so I used the “cd main_entrance” command. In order to find and read the instructions left by the friend I used the “ls” command followed by “cat instructions.txt”. To move back to the house folder I used the “cd ..” command to move one level backwards. Next I had to move to the kitchen by using the “cd kitchen” command. Using the “ls” command I found all the food and drink left around the house. Using the “rm” command I was able to remove items from the kitchen folder. By putting a / in between items when using the “rm” command such as “rm notes.txt/essays” you can remove multiple items in one command. Next I used the “ls -a” command to find the rotten bananas file. Using “rm” again, I was able to remove these files. Next I navigated to bedroom1 and then to bedroom2 by using the change directories command. When the lights went out, I used the “pwd” command to print my working directory to know where I am in the house. Next I went to the garage by using “cd garage”. Using “rm” I removed trash from each box. Finnaly I left a note by using “touch note.txt” then “echo “Thank you for trusting me!” > note.txt”.

Trouble Shooting Network Issues

In this activity we took out knowledge of the command line interface, on a Mac and VM, and used it to fix basic network issues on computers. Problems like these could be that your computer isn’t connecting to wifi or can’t look up a website.

Our class broke down the four steps to identifying the problem

Check whether your device is connected to the internet either by wifi or ethernet
Verify that you device has an ip address by going into the terminal and running ifconfig on a mac or ip addr on Ubuntu
Test whether your device can reach the internet at all by going into the terminal and pinging a common website like 8.8.8.8(google.com)
Test whether your device can reach the internet by website name, this could reveal problems with your DNS

These four steps should help when trying to identrify a networking issue.

Term	Definition
`Wi-Fi/Ethernet`	Signal carrier- connects your device to the internet .
`Network Adapter/Interface`	The hardware that lets your computer communicate with the internet ex. NIC (Network Interface Card).
`IP Address`	Identifiable address for devices within a network ex. 192.168.1.25 Private IPs : 10… , 192…, 172..,
`Defualt Gateway(Router)`	The device that connects your local network to the internet
`DNS(Domain Name System)`	Converts the IP address of websites into a user-readable format.
`Ping`	Tests connection between two devices within in a network Use: ping -c 4 8.8.8.8
`NAT/Shared networking(UTM)`	Pools all the IP addresses of devices within a network to create one IP address that identifies the network.
`Bridged Networking(UTM)`	Acts like a completely separate computer Gets its own IP address from the router.

Knowing these terms is imperative to success when troubleshooting networks using the command line interface

Using the Mac and Ubuntu terminals, we began exploring using networking commands. First running ifconfig on the mac to reveal our IP address. Looking at the response, next to en0: 10.12.25.202. en0 is the ip address of the computer you are on. When we disconnected the Wi-Fi we noticed that en1 dissapeared as en1 is your routers ip address. To test the computer ability to connect to the internet we ran ping -c 4 8.8.8.8 which was a success with an average response time of 7.222ms. Another way to determine if it was a success is if 0% packets were lost meaning all of the data made it to the server and back to your computer. Next we pinged cloudfare using ping -c 4 1.1.1.1. This was also a success with an average response time of 7.528ms. We determined that this difference in response time could be attributed to traffic on the server of the size of the server. Next we searched for the default gateway of our network or router. To execute this command you would use route -n get default on a mac and ip route on Ubuntu VM. Next we pinged the router using **ping -c 4 **. It was a success with an average response time of .847 ms. This speed is because the router is withing the same LAN as your computer. To test our DNS server we ran **ping -c google.com** this tests the DNS because the DNS converts website names like google.com into a readable ip address for your computer. After exploring on a mac device, we began using Ubuntu VM. We started by running **ip addr** to locate the ip address of the device we are on.

In the image you can see the ip address we found: 192.168.64.2/24.

Next we went over the differences between shared and bridged mode in Ubuntu VM. Shared is when the VM “hides” behind your Mac, using the Mac’s connection as its own. Bridged is when the VM acts like its own computer with its own connection.

We started Ubuntu VM in Shared mode to view the ip address. ip addr

Circled in red it the adapters name

Circled in blue is the ip address

Circled in green is the MAC address

Next, we changed to bridged mode and ran the same command

We noticed that in shared mode the ip address of the VM was the same as the Mac computer’s which makes sense because they share a connection in shared mode.

Reflection

By using the commands in multiple different activities I was able to solidify my understanding of these commands. Using visual tools like tree diagrams or the finder in Virtual Machines helped me better understand how to navigate using the terminal. Basic commands like “cd” or “rm” can be strung together to effieciently navigate through your computers files. These commands lay the foundation for my learning of the terminal. After learning the basic commands, I was then able to move to the networking commands. Using my knowledge of the terminal from the previous lessons, I was able to properly troubleshoot networking issues. When troubleshooting network issues you should always follow the four steps to identify your problem, then go about fixing it.