Guam Connectivity Degradation Lasted 11 Days, Severity Score 329,746

Guam experienced a significant connectivity disruption lasting over 11 days, beginning on July 5 and concluding on July 17. The event, which recorded a severity score of 329,746, primarily impacted active probing measurements across the island’s IPv4 address space.

Technical Details

The degradation was observed between 15:20 UTC on July 5 and 00:30 UTC on July 17, spanning 11.4 days. The primary affected signal was ping-slash24, a metric that measures ICMP reachability across IPv4 /24 network prefixes, which showed a 6% drop from its peak. The gtr-norm signal, which tracks deviations from expected traffic baselines, recorded a more substantial 62% drop from its peak. Backscatter measurements from the ucsd-nt signal also indicated a 67% decline. The BGP control plane, which advertises network routes, remained stable throughout the event with no observed drop.

The cause has not been publicly attributed. Connectivity was reported restored by the end of the observation period.