L'initiative est bonne (peu de prestas communiquent autant sur les incidents) mais le rapport manque encore de détails (marque(s) des appliances anti-DDoS, composition du trafic, description technique *précise* des problèmes rencontrés, ...).
« A new customer signed up for our service and brought in multiple domains that were already facing a DDoS attack. The customer had already tried at least 2 other providers before DNSimple. Once the domains were delegated to us, we began receiving the traffic from the DDoS.
[...]
The volume of the attack was approximately 25gb/s sustained traffic across our networks, with around 50 million packets per second. In this case, the traffic was sufficient enough to overwhelm the 4 DDoS devices we had placed in our data centers after a previous attack (there is also a 5th device, but it was not yet online in our network).
[...]
Second, even once the device was in place, the amount of traffic that was actually passed through the device caused our name server software to crash shortly after having receiving the volume of requests.
[ On note l'enseignement : lutter contre un DDoS, ce n'est pas uniquement un frontal à poser là et basta. ]
[...]
By about 6 AM UTC we had restored UDP traffic to the majority of our systems. We were still experiencing resolution failures for A records in our Amsterdam and Tokyo data centers, but other record types were resolving properly. After some research (many thanks to Peter van Dijk of PowerDNS for his help here), we decided to disable the DNS defense mechanism from DDoS protection device in the Amsterdam facility. Once we did this, all resolution returned to normal there.
We were still showing resolution issues with some public resolvers (such as Google's Public DNS). We went through the remaining data centers and removed the DNS defense mechanism from other DDoS protection devices and eventually we were able to get successful resolution from Google's public DNS.
[ Pas mal, ces dommages collatéraux. ]
We do not have the skills and budget to develop a complete DDoS solution internally. It is a very expensive endeavor and requires expensive equipment, lots of bandwidth, and deep knowledge on how to mitigate attacks. We have signed a contract with a well-known third-party service that provides external DDoS protection using reverse DNS proxies. Presently, our primary objective is to get all DNS traffic routed through the vendor first so that they can cache and deflect volumetric attacks like the one we just experienced.
[ La lutte anti-DDoS, une façon de centraliser le net ? Tout comme l'externalisation des mails (office365 par exemple), je me demande si une solution interne est vraiment plus coûteuse en terme de coûts directs (payer le presta "au fil de l'eau" versus investir matos+humain sur la durée) et indirects (effets collatéraux, dépendance à un presta, concentration des acteurs, risque d'attaques plus grand si tout est centralisé chez quelques prestas, ... ].
We are also well aware that one mitigation strategy is to allow customers to have secondary servers that can slave to our primary servers, and that this would have allowed many customers to continue operating, albeit at a possibly degraded level.
[ Ça c'est une "bonne" piste comparée à la précédente, je trouve. ] »
Via
https://twitter.com/jedisct1/status/540079258807189504