I'm just starting out with AWS and set up an instance with a public IP and a security group that allows inbound SSH and all outbound traffic by default. However, my subnet is private, which got me wondering. When I SSH into the public IP, will the SSH packets successfully reach the instance? Or will they be dropped due to the route table only affecting outbound traffic? I'm trying to learn more about AWS networking, but it feels quite overwhelming because I'm relatively new to networking concepts. Any tips would be greatly appreciated!
1 Answer
That's a good question! Route tables typically manage outbound traffic, but they do play a key role for inbound traffic as well. For your instance to respond correctly, the route table associated with your subnet needs to point to an Internet Gateway for the outbound route. Without that, you might not see responses coming back to your SSH requests, leading to confusion.
So just to clarify, will SSH packets even reach my instance in a private subnet without a route? Or will they get dropped before they arrive?