How to SSH using Linux and Mac – AWS Certified Cloud Practitioner

🖼️ How SSH Works

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      <span class="badge">🔒 Port 22</span>
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<div class="sf-detail" id="sf-detail-text">Tap a step, or hit connect ↓</div>

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Your Mac/Linux terminal → connects via internet
Through port 22 (SSH)
Into your EC2 instance (Amazon Linux 2)

⚙️ Step 1: Prepare Your Key File

👉 You downloaded: During EC2 instance creation phase

EC2 Tutorial.pem

⚠️ Important Fix

Rename it to remove spaces:

EC2Tutorial.pem

Place It in a Folder

Example:

aws-course/
 └── EC2Tutorial.pem

💻 Step 2: Navigate to Your File

Open terminal and go to your folder:

cd aws-course

Check if file exists:

ls

👉 You should see:

EC2Tutorial.pem

🧭 If You're Lost (Helpful Commands)

pwd     # shows current directory
ls      # lists files
cd ..   # go up one level
cd <folder-name>

🌐 Step 3: Get Your EC2 Public IP

From AWS Console:

Go to EC2 → Instances
Copy Public IPv4 address

Example:

3.250.xxx.xxx

🔐 Step 4: Check Security Group

Make sure your EC2 has:

✅ Port 22 (SSH) open
Source: 0.0.0.0/0

👉 If not → add it

🚀 Step 5: First SSH Attempt (Will Fail — That’s OK)

ssh ec2-user@<your-ip>

👉 Example:

ssh ec2-user@3.250.xxx.xxx

❌ You’ll likely see:

Permission denied / Authentication failure

👉 This is normal — you didn’t provide the key yet

🔑 Step 6: Use Your Key File

ssh -i EC2Tutorial.pem ec2-user@<your-ip>

❌ Step 7: Fix Permission Error

If you see:

UNPROTECTED PRIVATE KEY FILE!

👉 Run:

chmod 400 EC2Tutorial.pem

✅ Step 8: Connect Successfully

Run again:

ssh -i EC2Tutorial.pem ec2-user@<your-ip>

👉 First time:

Are you sure you want to continue connecting? (yes/no)

Type:

yes

🎉 You’re In!

You should now see:

ec2-user@ip-172-31-xx-xx:~$

🧪 Try These Commands

whoami

👉 Output:

ec2-user

ping google.com

👉 Stop with:

Ctrl + C

🚪 Step 9: Exit Instance

exit

🔁 Reconnect Anytime

ssh -i EC2Tutorial.pem ec2-user@<your-ip>

⚠️ Reminder: Public IP may change after stop/start

⚠️ Common Mistakes

❌ Wrong directory (can’t find .pem)
❌ Wrong permissions (forgot chmod 400)
❌ Missing port 22 in security group
❌ Typo in IP or filename