What is openWRT? OpenWrt can be described as an embedded Linux distribution. (mainstream router firmware dd-wrt, tomato, openwrt, padavan four class) compared to a single, static system, openwrt package management provides a completely writable file system, from the application suppliers selection and configuration, and allows you to customize the device, so as to adapt to any application.

The function of the openwrt

1. Openwrt can be used as a client to connect to other wifi as a WAN, and then create its own wifi as a LAN, which is equivalent to the wired WAN port to realize wifi Internet access without inserting a network cable. Other firmware seems to have no such setting mode, I don't know if I didn't find it. Usually, other firmware can only relay other wifi. The client is actually connected to the wifi of this relay, and the IP address is also assigned by the superior relay wifi, so it is not possible to create a sub-network through this router. The advantage of OpenwrT is that it connects to the Internet through wifi, creates a subnet by itself, and allows port mapping and rate limiting.

2. SSH tunnel

OpenWrt includes an SSH server so you can access its terminals. After exposing its SSH service to the network (don't forget to encrypt it with key authentication rather than a weak password), you can connect remotely and access it using SSH tunnel encryption. This allows you to use public Wi-Fi to access sites that are only accessible at home.

3. Set up VPN

SSH tunnels and VPNS are similar in many ways, but you can still build your own VPN on OpenWrt routes.

4. Install the BitTorrent client

If you have a specific network attached memory (NAS), or a router that comes with a USB port and a USB device, you can use the router as a BitTorrent client.

5. Run the server software

OpenWrt's software source includes packages that allow it to function as a Web server, such as IRCserver, BitTorrenttracker, and more. You're probably using a router, so why not just use that router as a server? A router uses much less power than a computer, so it's smart to use it as a lightweight server.

6. Traffic shaping service

OpenWrt lets you perform packet shaping on routed packets and check their quality of service (qos), assigning appropriate packets first. You can even assign a given packet to a given computer first and defer processing of packets assigned to other computers.

7. Create a VIP network

The OpenWrt wiki has instructions on how to set up a special wireless network for guests, which is separate from your main network for security purposes. You can even limit the speed of the VIP network.

8. Capture and analyze network traffic

You can use tcpdump to record all packets that pass through your router. You can then share it online or use tools like Wireshark to open it and analyze your network traffic and behavior.