FINDING · DETECTION
During apparent whitelist-activation periods on MTS mobile LTE, the affected user experienced a complete network blackout in which even explicitly whitelisted resources (gosuslugi.ru) were inaccessible — behavior inconsistent with a standard default-deny CIDR+SNI whitelist, which should pass approved destinations unconditionally. The operator concludes this may represent a stricter enforcement variant, a SIM-specific restriction, or a mechanism entirely separate from the documented whitelist architecture.
From 2026-amigocarra-bypassing-russian-federation-s — Bypassing the Russian Federation's mobile internet whitelists—we're stuck, looking for real-world experience · Issue body — main mystery paragraph · 2026 · net4people/bbs
Implications
- Do not assume Russia's mobile whitelist operates as pure CIDR+SNI default-deny; design for the possibility of complete carrier-side shutoffs that bypass the whitelist logic entirely and cannot be circumvented at the IP or TLS layer.
- Instrument clients to distinguish between 'whitelist active but target not listed' and 'full blackout including whitelisted sites' so support channels can triage which failure mode users face.
Tags
Extracted by claude-sonnet-4-6 — review before relying.