How to connect to an EC2 instance using SSH?

Difficulty: 4/10

SSH key management, Security groups, Network access

SSH Connection Process

Connecting via SSH is the standard method for managing Linux-based EC2 instances. You must have the private key (.pem file) generated during instance creation to authenticate securely.

SSH Command

Requirements

1
Ensure your private key file has restricted permissions (chmod 400).
2
The instance must have a public IP or be accessible via a bastion host.
3
Port 22 must be open in the associated Security Group.
4
Use the appropriate user for your AMI (e.g., ec2-user, ubuntu, admin).

Scenario Questions

0-2 years experience

2-5 years experience

1Our CI pipeline needs to run a script on a newly created EC2 instance via SSH, but the instance is in a private subnet with no public IP. How would you modify the setup to allow the script to connect securely?

Follow-up Questions