Japan experienced a significant connectivity disruption on September 2, 2026, lasting for over four hours. The event began around 18:20 UTC and concluded by 22:30 UTC, with a primary impact on network reachability. The disruption registered a severity score of 5,062 based on observed data.
Technical Details
The most affected metric was the ping-slash24 signal, which measures ICMP reachability across IPv4 /24 prefixes. This signal recorded a severity score of 5,062, with two distinct degradation periods observed between 18:20-21:30 UTC and 21:50-22:30 UTC. The signal’s value dropped by approximately 30% from its observed peak during the event.
Other network signals showed varying impacts. The gtr-norm signal, which tracks deviations from expected traffic baselines, recorded a 67% drop from its peak. The raw gtr traffic volume signal showed a more pronounced 73% decline. Control plane visibility, measured by the bgp signal, remained largely stable with minimal deviation. The cause has not been publicly attributed.
Connectivity was reported restored by the end of the observation window.
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