Recently to help customers deal with a DDoS event encountered the classic scenario - business suddenly penetrated, the source station IP exposure and even the database server were dragged down. These days even the CDN have to ‘defense teammates’, some service providers claim global acceleration, the attack came directly back to the source of the exposed IP, the so-called high defense is a pose.
Overseas business selection of high-defense CDN is not at all to see who has a large number of nodes, the key to look at the cleaning ability and network scheduling strategy. I have handled many cases of multinational enterprises, found that 80% of the customers planted in three pits: blind pursuit of low-priced packages, gullible ‘unlimited protection' publicity, ignoring the return link encryption. Last year, an e-commerce promotion during the 700Gbps traffic crash, is because of the use of a cheap CDN, the attack traffic has not reached the cleaning center blocked the cross-border backbone network.
After testing more than twenty service providers, I screened out three really can play high defense CDN. focus on four dimensions: cleaning center coverage density, TCP acceleration algorithm, vulnerability emergency response time, whether to support the direction of China optimization. Don't believe in those fancy console features, anti-attack ability all depends on the underlying infrastructure.
Let's start with CDN5, a veteran German vendor. Their family has built its own Tb-level cleaning centers in three core hubs in Frankfurt, Singapore and Los Angeles, and is especially good at dealing with application layer attacks. I simulated HTTP Flood last year with a pressure testing tool, and their intelligent routing system can dispatch traffic to the cleaning nodes within 3 seconds. The most critical is to provide false source IP protection, the attacker simply can not touch the real server location.
The configuration example requires changes to the nginx configuration to match their security token:
Don't expose the source IP directly! Their Anycast network comes with port stealth, and pinging the domain name will only return the cleaning node IP in the actual test. expensive but value for money, the lowest package starts at 299 euros per month, suitable for financial business.
The second recommended CDN07, the biggest advantage of this U.S. American node coverage perversion - 187 POP points around the world integrated AWS, GCP and Azure edge nodes. Especially suitable for sudden traffic huge live and game industry, I once helped a game customer configured their dynamic acceleration function, European and American users latency directly from 380ms down to 89ms.
Their WAF rule base is updated extremely quickly, and you can see new vulnerability protection rules added every week. Remember to turn on their ‘botnet challenge' feature, suspected attack traffic will be verified by JS before release. The test effectively blocked the 90% crawler attack, but note that this may affect some search engine inclusion.
Configuring their edge functions requires writing a simple piece of logic:
Now to the third 08Host, this Singaporean service provider is particularly suitable for Asia-Pacific business. They in Japan, Taiwan, Hong Kong layout of a large number of CN2 optimized lines, domestic access speed is comparable to the local CDN. the most critical is to provide free SSL certificates and anti-CC attack services, once resisted a last 4 days of ten million QPS CC attack.
I've actually tested their TCP acceleration algorithm, and it still maintains stable transmission on a cross-border link with a packet loss rate of 151 TP3T. The console is ridiculously simple, with just three switches: DDoS protection, smart compression, and zone blocking. Ideal for startup teams that don't want to fuss with technical details, the $59 per month price also includes a 2Tbps protection credit.
Note be sure to turn on their ‘safe back to source' feature:
Now on to the key selection recommendations. Financial business preferred CDN5, their compliance certification is the most complete; game video selection CDN07, burst traffic carrying capacity is the strongest; Asia-Pacific users mainly choose 08Host, latency optimization is indeed in place. Don't be fooled by the ‘unlimited protection' rhetoric, all high defense CDN has a hidden limit, more than the rated traffic directly null route.
Finally, a few pitfalls are reminded: avoid using shared IP packages, otherwise it is easy to be implicated by the neighbors; be sure to test whether the encryption of the return link is truly effective; check the scope of the service provider's BGP announcements, and the more ASNs covered by the cleansing node, the better. Last year, a customer chose a certain niche CDN to save money, and as a result, the attack traffic was black-holed by the upstream operator just after 300G.
The real protection effect also depends on the actual battle. It is recommended to do a simulation pressure test before the business is online, I commonly used mixed attack mode: SYN Flood + HTTP Slowloris + random URI crawler. Once measured a well-known CDN's WAF rule defects, their AI protection was even bypassed by a special cookie.
Nowadays, these providers offer free trials, but remember to always check key metrics during the test period: TCP retransmission rate from Hong Kong nodes to Los Angeles, response latency from European cleansing centers, and BGP routing from Asian nodes to China Mobile. The pretty monitoring graphs shown by some vendors are actually optimized demonstration routes.
In the end, high defense CDN is only a part of the security system, but also with the Web application firewall, zero-trust architecture and emergency response process. Last time I saw an outrageous case, the customer spent a lot of money to buy the top CDN, but because of the source code leakage led to the source station IP exposure - this is like buying a bulletproof door but the key is inserted in the door.
