2018-11-23
I was particularly interested in one of the consequences of how dynamic RAM works. You see, each bit of data is stored by the charge (or lack of it) on a tiny capacitor within the RAM chip. But these capacitors gradually lose their charge over time....
2018-11-12
It's been a while since we last wrote about Layer 3/4 DDoS attacks on this blog. This is a good news - we've been quietly handling the daily onslaught of DDoS attacks. Since our last write-up, a handful of interesting L3/4 attacks have happened. Let's review them....
2018-09-10
Back in 2015 we deployed ECMP routing - Equal Cost Multi Path - within our datacenters. This technology allowed us to spread traffic heading to a single IP address across multiple physical servers....
2018-07-06
Internally our DDoS mitigation team is sometimes called "the packet droppers". When other teams build exciting products to do smart things with the traffic that passed through our network, we take joy in discovering novel ways of discarding it....
2018-06-01
Cloudflare is protected from attacks by the Gatebot DDoS mitigation pipeline. Gatebot performs hundreds of mitigations a day, shielding our infrastructure and our customers from L3 and L7 attacks. ...
2018-04-17
In previous blog post we discussed how we use the TPROXY iptables module to power Cloudflare Spectrum. With TPROXY we solved a major technical issue on the server side, and we thought we might find another use for it on the client side of our product....
2018-04-12
Introducing Spectrum: a new Cloudflare feature that brings DDoS protection, load balancing, and content acceleration to any TCP-based protocol.Today we are releasing Spectrum. ...
2018-03-06
A week ago we published a story about new amplification attacks using memcached protocol on UDP port 11211. A few things happened since then: Github announced it was a target of 1.3Tbps memcached attack. OVH and Arbor reported similar large attacks with the peak reported at 1.7Tbps. ...
2018-02-27
Over last couple of days we've seen a big increase in an obscure amplification attack vector - using the memcached protocol, coming from UDP port 11211. In the past, we have talked a lot about amplification attacks happening on the internet. ...
2018-01-15
Here at Cloudflare, we have a lot of experience of operating servers on the wild Internet. But we are always improving our mastery of this black art. On this very blog we have touched on multiple dark corners of the Internet protocols: like understanding FIN-WAIT-2 or receive buffer tuning....
2017-11-07
In a recent blog post we discussed epoll behavior causing uneven load among NGINX worker processes. We suggested a work around - the REUSEPORT socket option....
2017-10-23
Scaling up TCP servers is usually straightforward. Most deployments start by using a single process setup. When the need arises more worker processes are added. ...
2017-09-25
In the past, we’ve spoken about how Cloudflare is architected to sustain the largest DDoS attacks. During traffic surges we spread the traffic across a very large number of edge servers. ...
2017-08-18
As opposed to the public telephone network, the internet has a Packet Switched design. But just how big can these packets be?...
2017-06-28
Last month we shared statistics on some popular reflection attacks. Back then the average SSDP attack size was ~12 Gbps....
2017-05-24
Recently Akamai published an article about CLDAP reflection attacks. This got us thinking. We saw attacks from Connectionless LDAP servers back in November 2016 but totally ignored them because our systems were automatically dropping the attack traffic without any impact....
2017-01-09
We extensively monitor our network and use multiple systems that give us visibility including external monitoring and internal alerts when things go wrong....
2016-12-05
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? ...
2016-10-11
Over the last few weeks we've seen DDoS attacks hitting our systems that show that attackers have switched to new, large methods of bringing down web applications....
