Lab Information
The Nautilus Development Team recently deployed a new web application hosted on an EC2 instance within a public VPC named xfusion-vpc. The application, running on an Nginx server, should be accessible from the internet on port 80. Despite configuring the security group xfusion-sg to allow traffic on port 80 and verifying the EC2 instance settings, the application remains inaccessible from the internet. The team suspects that the issue might be related to the VPC configuration, as all other components appear to be set up correctly. The DevOps team has been asked to troubleshoot and resolve the issue to ensure the application is accessible to external users.
As a member of the Nautilus DevOps Team, your task is to perform the following:
Verify VPC Configuration: Ensure that the VPC xfusion-vpc is properly configured to allow internet access.
Ensure Accessibility: Make sure the EC2 instance xfusion-ec2 running the Nginx server is accessible from the internet on port 80.
Lab Solutions
Step 1: Verify Internet Gateway (IGW) for xfusion-vpc
Go to VPC → Internet Gateways
Check if an Internet Gateway exists and is attached to xfusion-vpc
Select the IGW → Actions → Attach to VPC
Choose:
xfusion-vpc
✅ VPC now has a path to the internet
Step 2: Verify Route Table Configuration
Go to VPC → Route Tables
Identify the route table associated with the public subnet of xfusion-ec2
Check Subnet associations
Open Routes tab
Ensure this route exists:
Destination: 0.0.0.0/0
Target: Internet Gateway (igw-xxxx)
IPlease delete and add as New routes
Add route:
Destination: 0.0.0.0/0
Target: Internet Gateway
Save changes
✅ Subnet is now public
Step 3: Verify Subnet Auto-Assign Public IP
Go to VPC → Subnets
Select the subnet where xfusion-ec2 is running
Click Edit subnet settings
Ensure:
Enable auto-assign public IPv4 address ✔
Save
⚠️ If disabled, new instances won’t get public IPs automatically
Step 4: Verify EC2 Has a Public IP
Go to EC2 → Instances
Select xfusion-ec2
Check:
Public IPv4 address
Step 5: Final Internet Access Test
Open browser
Visit:
http://
✅ You should now see the Nginx Welcome Page
✅ Issue Resolved – Root Cause Identified
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