Hong Kong CN2 Server Packet Loss During Peak Hours: Check Local First, Test Return Route, Then Fix Line or Add Acceleration

Hong Kong CN2 servers often experience packet loss and higher latency between 20:00 and 23:00. Common causes fall into five categories: server load or bandwidth saturation, return route not using CN2 GIA, cross-network detours for China Mobile and China Unicom users, upstream bandwidth overselling, and small-scale attacks. This article provides a troubleshooting sequence: first check local load and NIC, then run bidirectional MTR during peak hours, then verify line type and differences among the three major networks, and finally choose the appropriate solution.