Recently helped an e-commerce station to do emergency response, encountered a crying situation: they spent a lot of money last year to buy a high defense CDN, the promotional page wrote "T-level protection", the results of the promotional activities just started ten minutes, the entire site was directly knocked down - the attack on the traffic is actually just 200G out of the head. The boss called to scold the service provider, the other party slowly came to a sentence: "you buy the basic package, peak defense only contains 100G, the excess part of the money to manually open" ...... this year, even CDN have to "defense teammates"?
High-defense CDN this thing, to put it bluntly is to the site invited a bodyguard. But the problem is that many companies think that they can rest easy after buying the service, in fact, most of the traditional high-defense CDN using a "static defense" model: to give you a fixed value of the defense, beyond the attack directly bypass the high-defense line road, or simply thrown into the black hole. Just like buying insurance when the salesman blew sky-high, really to claims only to find that the terms buried a bunch of pits.
I have tested the market seven or eight mainstream high-defense service providers, found three common pain points: the first is poor resilience, defense peaks can not be adjusted in real time on demand; the second is the switching delay is high, encountered a new type of mixed attacks when the rules come into effect slowly; the third is the cost is not controllable, unexpected traffic is often accompanied by sky-high bills. Especially when CC attacks and DDoS are mixed, the seven layers of protection of many CDNs are virtually useless.
Let's start with a counterintuitive point: the "defense value" of a high-defense CDN is actually a dynamic variable. It really depends on the size of the underlying resource pool and scheduling algorithms. For example, CDN5, the reason why they dare to promise "unlimited defense", because they are connected to the back of a number of clean traffic centers, can achieve nearly TB-level traffic scheduling. The so-called "T-level defense" of small vendors is often a mathematical game that piles all customer bandwidths together and counts them - when they really encounter a large-scale attack, the resource scramble collapses directly.
The first step in upgrading defense capability is to figure out your business characteristics. I usually recommend that customers use the "attack profile analysis" method: first, pull the attack logs of the last six months, and statistically identify the most frequent types of attacks, the peak traffic range, and the main source regions. For example, if a financial center finds that every Friday afternoon there are always about 200G of UDP floods, then it becomes the most cost-effective option to enable resilient protection during this time in advance.
In practice, I recommend the combination strategy of "baseline defense + resilience peak". The baseline defense uses a fixed package to carry the daily small-scale attacks, while the elastic part uses a pay-per-volume model. Like CDN07's "second elasticity" program is more realistic - attacks exceeding the threshold automatically triggered expansion, without manual approval, and defense granularity can be refined to the level of individual domain names.
The most critical aspect of the technical implementation is the API scheduling capability. A good high defense service should provide a complete API interface that allows us to dynamically adjust protection strategies through a self-built monitoring system. The following Python code is the elastic expansion trigger that I actually use in my client's system:
Some vendors API design is simply behavioral art - response latency of up to 30 seconds, waiting for the interface to return the results of the business early cold. So the test API performance must be written into the contract, requiring 99% requests to respond within 5 seconds. 08Host has planted in this piece, their elastic expansion API last year, the average response time of 12 seconds, and then sprayed by the customer to rewrite the entire scheduling system.
In addition to the expansion speed, the efficiency of the rules issued is also the lifeblood. Traditional CDN to update the WAF rules to the minute level, now the mainstream program are changed to use edge computing nodes compiled in real time. For example, using WebAssembly technology to protect the rules compiled into byte code sent to the edge of the CDN node, can be compressed to milliseconds effective time. This technical detail is ignored by many people, but it is precisely the key to dealing with fast variant attacks.
There's a blood lesson to be learned about cost control: don't buy into the 'unlimited defense' crap! All vendors have soft caps, and the only thing that is truly unlimited is your bill. Once a customer bought a certain "unlimited protection", the results of the month was hit 800G sustained attacks, the second month received a bill of one million two hundred thousand - the original contract corner wrote "excess traffic according to $0.05/GB billing".
Nowadays, the more advanced program is the "Intelligent Meltdown Mechanism". It not only adjusts the defense according to the attack traffic, but also makes decisions based on the importance of the business. For example, the business interface is divided into core transaction links and non-critical queries, and the protection level of non-core services is temporarily downgraded in extreme cases to protect the core business. This strategy helped an e-commerce platform save more than seven hundred thousand dollars in elastic protection fees during last year's Double Eleven.
Lastly, I'd like to mention a detail that many people have overlooked: the logs of a high-defense CDN must be used to feed the AI. simply write a Splunk query to find the attack pattern:
This data can not only optimize the protection strategy, but also in turn can whip the CDN vendors - last time is to take the log data to make CDN5 admit that their TCP stack has concurrent connection number vulnerability, and finally gave us a free upgrade of the protection cluster.
To be honest, the current high defense CDN market is like an arms race, the attacker is using AI to generate attack traffic, and the defender has to use machine learning to predict attack patterns. Among the several vendors tested recently, CDN07's "AI prediction expansion" is a bit interesting, which can predict the attack wave 5 minutes in advance through threat intelligence data and automatically warm up the protection resources. Although the accuracy rate is currently about 70%, it is already much stronger than the manual response.
If you really want to recommend a program, my suggestion is: daily use 08Host to carry small-scale attacks (cost-effective), large-scale activities before switching to the elastic protection of CDN5 (large pool of resources), when encountering advanced persistent threats to enable the AI protection mode of CDN07 (intelligent scheduling capabilities). Of course, the hardest defense is always the business layer to do the distributed and redundant design - CDN is just a means to buy time, the real line of defense still have to master themselves.
Finally throw a violent theory: in the next three years, 90% "high defense CDN" brand will disappear, either by the cloud vendors to be incorporated, or transformed to do security services. Now the play of these spelling resource pool sooner or later come to an end, and ultimately will certainly go to the edge computing + AI scheduling technology route. So now don't just look at the defense figures when selecting a model, and examine more of the vendor's R & D investment and API ecology, or else today's purchase of the "T-level defense", next year may become a digital legacy.
(After writing and looking at the monitoring alerts, another client was hit with a 380G Memcached reflection attack - gotta, tonight's noodles will have to be eaten on the traffic logs again ......)
