What could be responsible for the connection failure?
(Choose three.)
The NAT gateway in the subnet where the EC2 instance is deployed has been misconfigured.
The internet gateway of the VPC has been misconfigured.
The security group denies outbound traffic on ephemeral ports.
The route table is missing a route to the internet gateway.
The NACL denies outbound traffic on ephemeral ports.
The host-based firewall is denying SSH traffic.
Explanations:
The NAT gateway is used for instances in private subnets to access the internet. Since the bastion host is likely in a public subnet, the issue is not related to the NAT gateway.
The internet gateway could cause connectivity issues, but this is not the most likely cause since it is a VPC-level issue, and the error specifically points to SSH issues.
Security groups control inbound and outbound traffic to instances. However, outbound traffic on ephemeral ports typically wouldn’t block the connection, as it is not relevant for SSH.
A missing route to the internet gateway in the route table would prevent the EC2 instance from communicating with the internet, causing the SSH connection to time out.
Network ACLs (NACLs) may deny outbound traffic on ephemeral ports, which are used for communication during an SSH session, thus causing the connection timeout.
A host-based firewall, such as iptables on the EC2 instance, could block SSH traffic (port 22), resulting in a timeout error when trying to connect via SSH.
I rate that the answer is:
The route table is missing a route to the internet gateway.