Server name is required
Port is required
Valid subnet is required (e.g., 10.0.0.0/24)
MTU must be between 1280 and 1440
Recommended: 1280 for basic internet, 1420-1440 for better performance
Valid DNS servers required (comma-separated IPs)
Comma-separated DNS server IPs (e.g., 8.8.8.8,1.1.1.1)
Changing NAT or LAN blocking requires iptables reapply (handled automatically on server start).