title: Can't SSH into AWS EC2 instance
body: <p>I can't SSH into my EC2 instances - I am getting a timeout error. I checked the security groups to ensure that SSH traffic is working. I checked the routing tables and ensured that they are connected to an internet gateway. I was able to SSH into the instances just an hour ago but no longer. I am connecting via Putty. I had the same timeout issue connecting before using ec2-user@domain which I solved by simply entering the ip address into the hostname field in Putty. At that point I was able to connect without a problem. I then created another EC2 instance and now I cannot connect to either instance. I have the .ppk file being correctly referenced in my Putty config. I tried connecting with a mac and copying the .pem file there. Is there anything else I can check? Also, why could I not type ec2-user@domain into the connection field in putty like the directions indicate. Is there something wrong with my AWS environment?</p>