📖 What is SSH (Secure Shell)?
Secure Shell (SSH) is a cryptographic network protocol used for operating network services securely over an unsecured network. It provides a secure channel for remote command-line login and other secure network services, replacing the insecure Telnet protocol.
"Always choose SSH over Telnet for remote management because SSH encrypts the session, whereas Telnet sends credentials in plain text."
📚 Certification: CompTIA A+ Certification Exam Core 1 (220-1101)
🔑 What are the Key Concepts of SSH (Secure Shell)?
- ▸ SSH encrypts all traffic, including usernames and passwords, preventing eavesdropping and man-in-the-middle attacks on unsecured networks.
- ▸ The protocol typically operates on TCP port 22, which is a critical detail for configuring firewalls and troubleshooting remote connectivity.
- ▸ It supports multiple authentication methods, including standard passwords and public-key authentication using a private and public key pair for enhanced security.
- ▸ SSH serves as the secure replacement for Telnet, as it eliminates the risk of credentials being transmitted in cleartext across the network.
- ▸ SSH provides the secure foundation for SFTP, allowing administrators to transfer files securely over the same encrypted channel used for remote management.
🎯 How does SSH (Secure Shell) appear on the 220-1101 Exam?
You may be asked to identify the most secure protocol for managing a remote server or network switch in a scenario where Telnet is listed as an alternative, requiring you to prioritize encryption.
A scenario might describe a technician needing to configure a corporate firewall to allow remote administrative access; you must identify TCP port 22 as the correct port to open.
Expect questions where you must differentiate between SFTP and FTP, specifically focusing on which protocol utilizes SSH to protect sensitive data and credentials during the file transfer process.
❓ Frequently Asked Questions
Why is SSH preferred over Telnet for remote management?
Telnet sends all data, including login credentials, in plain text, making it vulnerable to packet sniffing. SSH encrypts the entire session, ensuring that sensitive information remains confidential and protected from attackers during transmission.
What is the difference between SSH and SFTP?
SSH is the underlying protocol used for secure remote command-line access. SFTP is a specific file transfer protocol that runs over an SSH session to provide secure, encrypted file movement between systems.