Initial Security Assessment

Before implementing security measures, understanding your current SSH configuration's vulnerabilities provides a baseline for improvement. Default SSH installations often include settings optimized for compatibility rather than security, leaving servers exposed to various attack vectors.

Perform an initial security audit of your SSH configuration:

# Check current SSH version
ssh -V
# OpenSSH_8.x or later recommended for latest security features

# Review current configuration
sudo sshd -T | grep -E 'permitrootlogin|passwordauthentication|pubkeyauthentication|protocol'

# Scan for weak configurations
sudo grep -v '^#' /etc/ssh/sshd_config | grep -v '^$' | sort

# Test current security posture
ssh -vvv localhost 2>&1 | grep -E 'debug1: kex:|debug1: cipher:|debug1: mac:'

Identify running SSH services and their ports:

# Check listening SSH ports
sudo netstat -tlnp | grep sshd
sudo ss -tlnp | grep sshd

# Verify SSH daemon status
sudo systemctl status sshd
sudo systemctl is-enabled sshd

# Review SSH process details
ps aux | grep sshd