As a Pro AWS Solutions Architect, I Can’t Believe I Just Found This Out about Subnets!

We all have those moments in tech where we stumble across a setting and think, “Wait, how did I not know this?”

Well, let me share mine with you — because if you’re dealing with AWS networking, this might save you a couple of hours or even days of frustration.

What Happened

I recently created a new subnet manually, and everything seemed perfectly set up. I configured my route table to point to the Internet Gateway (IGW). I reused an old Launch Template for EC2 instances. But after launching a new instance, surprise, surprise — it had no access to the internet.

I went through the configurations and I thought it was just a minor thing:

• Internet Gateway? ✅
• Route Table? ✅
• Security Groups? ✅

They are all set good!

At this point, I thought, “What on earth am I missing?”

The Missing Piece: Auto-Assign Public IP in Subnet Settings

After diving deep, I found the issue buried where I didn’t expect it — in the subnet settings.