On Sunday 10 October 2021 at 00:34 UTC, a GRE flood targeted a crypto exchange customer in North America. The attack peaked at 206.5 Gbps and lasted 132 minutes. Traffic originated from 1001 autonomous systems in 94 countries, predominantly misconfigured open reflectors.
| Vector | GRE flood |
| Peak | 206.5 Gbps |
| Duration | 132 min |
| Time to mitigation | 0.600 s |
| Attack traffic reaching origin | 0.000% |
| Legitimate traffic challenged | 0.66% |
Timeline
The attack was preceded by a breaking political story. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 28 points of presence.
What the customer saw
A brief increase in p99 latency of 130 ms during the first minute, then normal service.
Recommendations
- Review allow-listed partner ranges quarterly.
- Enable authenticated origin pulls.
- Enable log streaming to your SIEM for faster correlation.