Iran's Internet Shutdown: Key Technical Details and Practical Implications

In late December 2025, widespread protests in Iran led to a near-total shutdown of the country's Internet connectivity. Cloudflare Radar data reveals a significant drop in Internet traffic from Iran, with IPv6 traffic plummeting from 12% to 2% of human-generated traffic. The shutdown was characterized by a 98.5% reduction in announced IPv6 address space, indicating an intentional disruption to Internet connectivity.

Technical Observations

• On January 8, at 11:50 UTC, the amount of IPv6 address space announced by Iranian networks dropped by 98.5%, indicating a major disruption to Internet connectivity.
• Between 16:30 - 17:00 UTC, traffic volumes from major Iranian network providers, including MCCI, IranCell, and TCI, fell nearly 90%.
• By 18:45 UTC, Internet traffic from Iran dropped to effectively zero, signaling a complete shutdown in the country and disconnection from the global Internet.

Practical Implications for Developers

• The shutdown highlights the importance of monitoring Internet traffic and connectivity in regions prone to disruptions.
• Developers should consider implementing redundancy and failover mechanisms to ensure continued access to critical services.
• The use of Cloudflare's public DNS resolver, 1.1.1.1, may provide a temporary workaround for accessing Internet services during shutdowns.