# Advanced

- [Firewall](/advanced/firewall.md): The router firewall controls the forward packet streams from incoming network interfaces to outgoing network interfaces.
- [Dynamic DNS](/advanced/ddns.md): Dynamic DNS allows the router to reach a fixed hostname while having a dynamically changing IP address.
- [Traversal Cloud](/advanced/traversal-cloud.md): Traversal Cloud is a secure NAT tunnel tool to provide remote control function on the 4G outdoor routers and connected hosts.
- [Terminal](/advanced/terminal.md): The command-line interface (CLI) means interacting with the router system where the user issues commands to the router system through command lines.
- [Web Port](/advanced/web-port.md): Guidance of how to change the Web GUI interface port on the outdoor router.
- [VPN Tunnels](/advanced/vpn-tunnels.md): The outdoor router has integrated both OpenVPN and WireGuard protocols.