Network Security Hardening Guide

What's Inside

A comprehensive, actionable guide to hardening your network — distilled from 100+ GeniusTechLab posts on networking, security, and homelab hardening. Whether you're running a home network, a small business, or a homelab with 50+ services, these are the steps that matter most.

Sections Covered

• Network Architecture Principles (5 rules, hub-and-spoke model)
• VLAN Segmentation Strategy (5-VLAN layout with inter-VLAN rules)
• Firewall Configuration (OPNsense/pfSense baseline rules + hardening checklist)
• VPN Hardening with WireGuard (config templates, PSK, key rotation)
• DNS Filtering with AdGuard Home (blocklists, DoH, DNS firewall rules)
• IDS/IPS Deployment (Suricata setup, performance benchmarks, rule tuning)
• Wireless Security (WPA3, SSID strategy, PMF, band steering)
• Endpoint Hardening (Linux server + Docker host hardening scripts)
• Monitoring & Alerting (Prometheus/Grafana stack, alert thresholds)
• Incident Response Checklist (contain → assess → eradicate → recover)
• Quarterly Security Audit Checklist (30+ items)

Sample: VLAN Segmentation Strategy

Sample: WireGuard Configuration

[Interface]
Address = 10.0.50.1/24
ListenPort = 51820
PrivateKey = <server-private-key>

PostUp = iptables -A WG-INPUT -i wg0 -m state --state ESTABLISHED,RELATED -j ACCEPT
PostUp = iptables -A WG-INPUT -i wg0 -d 10.0.20.0/24 -j ACCEPT
PostUp = iptables -A WG-INPUT -i wg0 -j DROP

[Peer]
PublicKey = <client-public-key>
PresharedKey = <preshared-key>
AllowedIPs = 10.0.50.2/32

Sample: Linux Server Hardening Script

# SSH hardening
sed -i 's/#PermitRootLogin.*/PermitRootLogin no/' /etc/ssh/sshd_config
sed -i 's/#PasswordAuthentication.*/PasswordAuthentication no/' /etc/ssh/sshd_config
sed -i 's/#Port.*/Port 2222/' /etc/ssh/sshd_config
systemctl restart sshd

# Install fail2ban + AIDE
apt install -y fail2ban aide
systemctl enable fail2ban
aideinit