# Network & Security Configuration

Complete guide for securing and networking your homelab.

## SSH Security Setup

### Initial Configuration
```bash
# Generate SSH key pair
ssh-keygen -t ed25519 -C "homelab-key" -f ~/.ssh/homelab_ed25519

# Copy public key to target
ssh-copy-id -i ~/.ssh/homelab_ed25519.pub user@target
```

### SSH Hardening
Edit `/etc/ssh/sshd_config`:
```
# Disable root login
PermitRootLogin no

# Use key-based authentication only
PasswordAuthentication no
PubkeyAuthentication yes

# Change default port (optional)
Port 2222

# Restrict users
AllowUsers hoborg

# Security settings
Protocol 2
X11Forwarding no
AllowTcpForwarding no
ClientAliveInterval 300
ClientAliveCountMax 2
MaxAuthTries 3
MaxStartups 2
```

Restart SSH: `sudo systemctl restart sshd`

### SSH Client Configuration
Create `~/.ssh/config`:
```
Host homelab
    HostName your-domain.duckdns.org
    User hoborg
    Port 2222
    IdentityFile ~/.ssh/homelab_ed25519
    ServerAliveInterval 60
```

## Dynamic DNS with DuckDNS

### Account Setup
1. Create account at duckdns.org
2. Create subdomain: `ak-homelab.duckdns.org`
3. Get token from dashboard

### Automatic IP Updates
Update script at `~/.local/scripts/duckdns.py` (Python implementation)

Cron job for automatic updates:
```bash
# Update every 5 minutes
*/5 * * * * /home/hoborg/.local/scripts/duckdns.py >/dev/null 2>&1
```

### Testing
```bash
# Check current IP
curl -s https://ipinfo.io/ip

# Verify DNS resolution
nslookup ak-homelab.duckdns.org
```

## VPN Setup with WireGuard

### Server Configuration
Install WireGuard: `pacman -S wireguard-tools`

Generate keys:
```bash
wg genkey | tee server_private.key | wg pubkey > server_public.key
```

Server config `/etc/wireguard/wg0.conf`:
```ini
[Interface]
PrivateKey = <SERVER_PRIVATE_KEY>
Address = 10.0.0.1/24
ListenPort = 51820
PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -A FORWARD -o %i -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -D FORWARD -o %i -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE

[Peer]
PublicKey = <CLIENT_PUBLIC_KEY>
AllowedIPs = 10.0.0.2/32
```

### Client Configuration
Generate client keys:
```bash
wg genkey | tee client_private.key | wg pubkey > client_public.key
```

Client config:
```ini
[Interface]
PrivateKey = <CLIENT_PRIVATE_KEY>
Address = 10.0.0.2/24
DNS = 1.1.1.1

[Peer]
PublicKey = <SERVER_PUBLIC_KEY>
Endpoint = ak-homelab.duckdns.org:51820
AllowedIPs = 0.0.0.0/0
PersistentKeepalive = 25
```

### Enable VPN
```bash
sudo systemctl enable wg-quick@wg0
sudo systemctl start wg-quick@wg0
```

## Firewall Configuration

### UFW Setup
```bash
# Install and enable UFW
pacman -S ufw
sudo ufw enable

# Default policies
sudo ufw default deny incoming
sudo ufw default allow outgoing

# SSH access
sudo ufw allow 2222/tcp

# WireGuard
sudo ufw allow 51820/udp

# HTTP/HTTPS for services
sudo ufw allow 80/tcp
sudo ufw allow 443/tcp
```

### Advanced Rules
```bash
# Rate limiting for SSH
sudo ufw limit 2222/tcp

# Allow from specific networks
sudo ufw allow from 192.168.1.0/24 to any port 22

# Log denied connections
sudo ufw logging on
```

## Network Security Best Practices

### Port Management
- **Change default ports**: SSH (2222), WireGuard (51820)
- **Close unused ports**: Regular port scans with nmap
- **Port forwarding**: Only forward necessary ports

### Access Control
- **VPN-first approach**: Access services through VPN tunnel
- **IP whitelisting**: Restrict access to known IPs when possible
- **Rate limiting**: Prevent brute force attacks

### Monitoring
- **Log analysis**: Monitor `/var/log/auth.log` for SSH attempts
- **Network monitoring**: Use netstat/ss to check listening ports
- **Intrusion detection**: Consider fail2ban for automated blocking

## Router Configuration

### Port Forwarding
Forward these ports to your homelab server:
- SSH: External port → Internal 2222
- WireGuard: 51820 → 51820
- Web services: 80/443 → 80/443 (if needed)

### Security Settings
- **Disable WPS**: Turn off WiFi Protected Setup
- **Strong WiFi password**: WPA3 with complex passphrase
- **Guest network**: Separate network for guests
- **Firmware updates**: Keep router firmware current

## Network Planning

### IP Address Scheme
- **Router**: 192.168.1.1
- **Homelab server**: 192.168.1.100 (static)
- **DHCP range**: 192.168.1.10-99
- **VPN subnet**: 10.0.0.0/24

### DNS Configuration
- **Primary DNS**: Router (192.168.1.1)
- **Secondary DNS**: 1.1.1.1, 8.8.8.8
- **Local domain**: homelab.local
- **Dynamic DNS**: ak-homelab.duckdns.org

### Service Architecture
```
Internet → Router → Homelab Server
                 ↓
    ┌─────────────────────────────┐
    │  SSH (2222)                 │
    │  WireGuard VPN (51820)      │
    │  Web Services (80/443)      │
    │  Monitoring & Logging       │
    └─────────────────────────────┘
```

## Backup and Recovery

### Configuration Backups
- **SSH keys**: Store securely, separate from server
- **WireGuard configs**: Document peer configurations
- **Firewall rules**: Export UFW rules with `ufw status numbered`

### Network Documentation
- **IP mappings**: Document static assignments
- **Port forwards**: List all forwarded ports and purposes
- **Access credentials**: Secure storage of passwords/keys