First Move (11~18) - Code, Learn, Build
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First Move (11~18) - Code, Learn, Build

Structured, level-based technology learning paths from foundational exploration to industry mastery.

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← Linux Systems & Security|Level 3: Linux Security Hardening, Firewalls & SSH

5. Hardened SSH Administration & UFW Firewall Configuration

Lesson 5 of 6
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Hardened SSH Administration & UFW Firewall Configuration

Configure SSH key-based authentication, disable password login, change default SSH port, and configure UFW firewall rules.

SSH Hardening & UFW Policies

### Critical SSH Hardening Settings (`/etc/ssh/sshd_config`) - `PermitRootLogin no`: Prevents direct SSH login as root. - `PasswordAuthentication no`: Disables password login, forcing public key authentication (`ssh-ed25519`). - `Port 2222`: Changes default SSH port to mitigate automated brute-force scanners.
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