Upgrade the Fast Rhino R68 router to the latest Lean OpenWrt firmware and conduct WAN to LAN throughput tests using OpenSpeedTest and iPer3. Follow along as the video demonstrates the upgrade process, changes settings in LuCI, and performs various tests to optimize network performance. Explore different configurations including disabling offloading, enabling packet steering, and changing CPU governor settings. Analyze the results of throughput tests under different conditions, with a focus on understanding the 1600 Mbps throughput limitation. Learn about network diagrams, iperf3 testing, and potential optimization strategies for the Fast Rhino R68s router.