How can I troubleshoot and resolve the particular issue of “instance reachability check failed”?

In the context of AWS, you can troubleshoot and resolve the issue of “Instance reachability check failed”:-

Verifying Instance status

You should start by checking the status of the affected EC2 instances in the management console related to AWS or you can also use the command line interface of AWS:-

 Aws ec2 describe-instance-status –instance-id

Checking system logs

You can try to review the system log of the instance for the task of identifying any underlying issues or even errors:-

Aws ec2 get-console-output –instance-id

Checking security group rules

Try to ensure that the security group that is associated with the Instance allows inbound and outbound traffic necessary for its operations. You can then verify and update the security group rules by using the AWS management console or the command line interface of AWS.