May 19, 2017: OCSP and Issuance Outage Postmortem
https://community.letsencrypt.org/t/may-19-2017-ocsp-and-issuance-outage-postmortem/34922 [community.letsencrypt.org]
2017-05-25 19:46
Merging repeated slashes is such a common behavior that we had to disable it in three separate places.
We got their customer service on the phone, at which point we learned about the DDoS scrubbing and requested they turn it off. They did, but our connectivity problem continued. After more phone calls and escalations, we learned that there was actually a second DDoS mitigation in place, at their upstream ISP.
Too many slashes, too many mitigations, too many turtles.
source: L