Vpn Implementation Patterns

VPN Implementation Patterns

Implementing VPN tunnels and remote access — from WireGuard and OpenVPN through IPsec/IKEv2, site-to-site VPNs, and remote access design patterns.

When to Use

• Providing secure remote access for employees
• Connecting branch offices via site-to-site VPN
• Building secure communication between cloud and on-premise
• Implementing zero-trust network access alongside VPN
• Replacing legacy VPN with modern alternatives

VPN Protocols

VPN_PROTOCOLS = {
    'wireguard': {
        'strength': 'Modern, fast, simple, kernel-level, audited',
        'use_case': 'General purpose, site-to-site, remote access',
        'setup': 'Minimal config, single file, public/private keys',
    },
    'openvpn': {
        'strength': 'Mature, widely supported, rich auth options',
        'use_case': 'Remote access, enterprise, complex auth needs',
        'setup': 'Certificate-based, more config options',
    },
    'ipsec': {
        'strength': 'Industry standard, hardware offload, strong encryption',
        'use_case': 'Site-to-site, cloud-to-on-premise, legacy compatibility',
        'setup': 'IKEv2 with strongSwan or built-in OS support',
    },
}

# WireGuard config template
WIREGUARD_CONFIG = """
[Interface]
PrivateKey = <server-private-key>
Address = 10.0.0.1/24
ListenPort = 51820

[Peer]
PublicKey = <client-public-key>
AllowedIPs = 10.0.0.2/32
"""

Common Pitfalls

1. Split tunneling not configured — all traffic through VPN slows internet access; route only private ranges
2. Key management — WireGuard keys on compromised clients; implement key rotation
3. No failover — single VPN server = single point of failure; cluster or have backup
4. MTU issues — VPN encapsulation reduces MTU; adjust MTU (typically 1420 for WireGuard)
5. Performance bottleneck — VPN server CPU can't handle throughput; consider kernel-level WireGuard

Verification Checklist

• Protocol selected (WireGuard, OpenVPN, IPsec)
• Split tunneling configured (only route private IPs)
• Authentication method defined (keys, certificates, SSO)
• MTU configured correctly
• Firewall allows VPN protocol on correct port
• DNS configuration for internal resources
• Monitoring on connection count, bandwidth, errors
• Revocation process for compromised devices
• Failover/high availability for production VPN