Log-in to Amazon Web Services and check the followings:
- Security Group for your instance is allowing Inbound SSH access (check: view rules).
- For VPC instance, check its attached Route table which should have
0.0.0.0/0
as Destination and your Internet Gateway as Target. - Double check your route info in System Log in Networking of the instance.
For more details, check: Troubleshooting Connecting to Your Instance