FINDING · EVALUATION
GFW DNS filtering effectiveness shows diurnal variation: correct response rates are lowest in the early morning hours (before 6:00 a.m.) and rise throughout the day, suggesting filtering devices fail to process all DNS queries during peak traffic periods. However, the overall variance across time is small — maximum standard deviation of 0.03 — indicating the filtering mechanism is broadly stable over the 40-day measurement window.
From 2022-cheng-in-depth — In-Depth Evaluation of the Impact of National-Level DNS Filtering on DNS Resolvers over Space and Time · §4.3, Figure 11 · 2022 · Electronics
Implications
- Circumvention tools that rely on DNS-based bootstrapping may have marginally higher success rates during high-traffic periods when GFW filtering devices are overloaded, but the gain is small (<3% std dev) and not a reliable bypass strategy.
- Monitoring-based adaptive retry (retrying DNS resolution during predicted peak hours) is unlikely to yield significant improvement and should not be prioritized over structural bypasses like encrypted DNS.
Tags
Extracted by claude-sonnet-4-6 — review before relying.