Flash Report 2025.8.20 | GFW Suspected of Large-Scale Interference with Port 443 Connections Starting tonight, users in multiple regions have reported that China’s “Great Firewall” (GFW) appears to be conducting high-intensity interference against port 443, primarily manifesting as severe packet loss and connection timeouts. The details are as follows: Overseas to domestic access: When connecting to websites within mainland China via port 443 (commonly used for HTTPS), frequent packet loss and disconnections occur, making stable connections impossible. Domestic to overseas access: Users within China have likewise reported being unable to access overseas sites via port 443, with the HTTPS connection failure rate rising significantly. Port 80 unaffected: By comparison, access over port 80 (HTTP) remains largely normal, indicating that the interference is concentrated on port 443. At present, the technical community widely speculates that this phenomenon may be related to network policy adjustments or firewall rule changes. The exact cause remains to be confirmed, and the scope and duration of its impact require further observation....
