> For the complete documentation index, see [llms.txt](https://indoor.router.works/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://indoor.router.works/ezr23/advanced.md).

# Advanced

- [Firewall Settings](https://indoor.router.works/ezr23/advanced/firewall-settings.md): The router firewall controls the forward packet streams from incoming network interfaces to outgoing network interfaces.
- [Dynamic DNS](https://indoor.router.works/ezr23/advanced/dynamic-dns.md): Dynamic DNS allows that your router can be reached with a fixed hostname while having a dynamically changing IP address.
- [Traversal Cloud](https://indoor.router.works/ezr23/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.
- [Command-line](https://indoor.router.works/ezr23/advanced/command-line.md): The command-line interface (CLI) means interacting with the router system where the user issues command to the router system in the form of command lines.