Remotely-triggered blackhole events occur when a DDoS attack’s traffic against a resource reaches a DigitalOcean specified mitigation limit. At that point, DigitalOcean’s traffic scrubbers reach their limit and can no longer mitigate the attack. When this occurs, DigitalOcean temporarily reroutes your traffic (triggers a blackhole) to prevent it from reaching your resources and causing downtime.
While the vast majority of DDoS attacks never reach this threshold, here are some steps you can take if you experience a blackhole event: