Timeweb Cloud

TSPU Filtering Disrupts Timeweb Cloud Servers: Diagnosis, CDN Failures, and Reverse Proxy Bypass

Russian hosting provider Timeweb Cloud experienced widespread TSPU-based DPI filtering starting in early June that selectively blocked TLS handshakes on port 443 while leaving SSH, ICMP, and TCP connectivity intact. The issue affected multiple providers including Beget and Selectel, was publicly acknowledged by Timeweb on June 5, and proved highly variable by region, operator, and time of day. Attempts to mitigate via new IP addresses or Timeweb's own CDN failed due to poisoned caches and platform outages, while Yandex Cloud CDN blocked all POST requests required for WordPress functionality. A working solution involved deploying a minimal nginx reverse proxy on another Russian cloud VPS that preserves full HTTP methods, handles certificate synchronization, and routes ACME challenges correctly. Timeweb support later closed tickets without resolution after requesting ineffective mtr traces that cannot detect DPI behavior. The case highlights systemic challenges in diagnosing state-mandated filtering and the limitations of standard network diagnostics against selective TLS interference.