Debugging war story: the mystery of NXDOMAIN

Published on by Ivan Babrou.

The following blog post describes a debugging adventure on Cloudflare's Mesos-based cluster. This internal cluster is primarily used to process log file information so that Cloudflare customers have analytics, and for our systems that detect and respond to attacks. The problem encountered didn't have any effect on our customers, but did have engineers scratching their heads... The Problem At some point in one of our cluster we started…

TLD glue sticks around too long

Published on by Marek Majkowski.

Recent headline grabbing DDoS attacks provoked heated debates in the DNS community. Everyone has strong opinions on how to harden DNS to avoid downtime in the future. Is it better to use a single DNS provider or multiple? What DNS TTL values are best? Does DNSSEC make you more or less exposed? CC BY 2.0 image by Leticia Chamorro These are valid questions worth serious discussion, but…

Will autocrats ever learn? - The Internet Blackout in Gambia

Published on by Michael Nelson.

On Wednesday afternoon, Cloudflare and other Internet companies noticed that the West African country of The Gambia had dropped off the Internet - the day before the presidential election that was planned to be held there on Thursday, December 1st. This is not unprecedented. The Ugandan government blocked access to Facebook and WhatsApp during its recent election. Internet blocking by governments has also been seen in Gabon. Even…

The Daily DDoS: Ten Days of Massive Attacks

Published on by John Graham-Cumming.

Back in March my colleague Marek wrote about a Winter of Whopping Weekend DDoS Attacks where we were seeing 400Gbps attacks occurring mostly at the weekends. We speculated that attackers were busy with something else during the week. This winter we've seen a new pattern, and attackers aren't taking the week off, but they do seem to be working regular hours. CC BY 2.0 image by Carol…

Not one, not two, but three undersea cables cut in Jersey

Published on by Martin J Levy.

Sometime before midnight Monday (UK local time) a ship dropped its anchor and broke, not one, not two, but three undersea cables serving the island of Jersey in the English Channel. Jersey is part of the Channel Islands along with Guernsey and some smaller islands. Image courtesy TeleGeography Submarine Cable Map These things happen and that’s not a good thing. The cut was reported on the venerable…