Hello, I am Lao Li, a live broadcast and network security in the field of more than a decade of mixing the old oil. Today we do not talk about false, on the live broadcast of the DDoS attacks that people can not sleep at night - this thing once attacked, push the stream card into the PPT, pull the stream directly disconnected, the audience cursed, the platform dropped powder, the boss slapped the table, the scene is simply worse than the scene of the car accident. I remember last year to help a friend to deal with their live platform, because of a simple DDoS, online users from tens of thousands to zero, heavy losses ah. So, today I will share some dry goods, how to use high defense CDN to carry these attacks, so that the live broadcast is as stable as the old dog.
Speaking of DDoS, it's nothing new, but the attacks against live streaming are particularly nasty. Live streaming push and pull streaming is essentially real-time data transmission, push streaming is the anchor side of the video stream to the server, pull streaming is the audience side of the server to get the stream.DDoS attacks come up, the crazy send garbage requests, crowded bandwidth and server resources, resulting in the interruption of the push streaming (the anchor can not send out) or pull the streaming lagging (the audience can not see). I found that the common types of attacks like SYN Flood, UDP Flood, and even the application layer HTTP Flood, can easily defeat the ordinary CDN. don't believe those who bragged about the “self-protection” of the cheap CDN, I've seen too many cases, once encountered a large amount of traffic attacks on the direct knee, even a warning! There is no warning.
Why is live streaming so fragile? Because it is extremely sensitive to latency and bandwidth. Push stream interruption means that the anchor has to reconnect, and may lose frames or drop the line; pull stream interruption, the audience experience is poor, the churn rate soared. These days, even CDNs have to “defend themselves against teammates” - some attacks even come from internal misconfigurations or malicious competition. For example, last year I used the tool to simulate a small-scale DDoS, an unprotected live node test, the results of the push-flow delay from 50ms soared to more than 500ms, pulling the stream buffer time increased by 10 times, completely unable to see. Data comparison down, unprotected nodes in the 100Mbps attack on the collapse, while high-defense CDN can easily carry 1Gbps or even higher.
OK, enough trolling, let's get to the point - the solution. High-defense CDN is not magic, but it defuses attacks through distributed nodes and intelligent cleaning. The core idea is to direct traffic to the protection node, filter out malicious requests, and only release legitimate traffic to the source station. I recommend the self-built program combines a CDN and WAF (Web Application Firewall), tested down the effect of the bar. Let's talk about the configuration, here is a simple Nginx reverse proxy example for pushing the flow side of the protection. Never directly expose the source IP, otherwise the attacker touches, you are finished.
This configuration is just the base, the real environment has to be combined with the features of the CDN service provider. I have compared several mainstream service providers, such as CDN5, CDN07 and 08Host. CDN5 has the advantage of large bandwidth, cleaning ability - I have tested it, it can automatically detect and mitigate the attack of millions of requests per second, the delay increased less than 5%, suitable for large traffic live. But the disadvantage is that it is expensive, the monthly cost may be tens of thousands of small platforms can not carry. CDN07 is more flexible, providing custom rules, such as geographic location-based shielding, I helped a game live platform used, successfully blocked the source of attacks from a specific region. 08Host is the king of price-performance ratio, the cleaning effect is medium, but the price is pro-people, suitable for startups; however, do not expect it to carry a super large-scale Attacks, I test, more than 500Mbps is a little tight.
Data to speak: in the simulation test, CDN5 in the 1Gbps attack, push flow interruption time is 0, pull flow delay stays within 100ms; CDN07 in 800Mbps when the performance is stable, but any higher will have to be manually tuned; 08Host in the 300Mbps below the problem, more than that, you have to add money to upgrade. Therefore, the selection depends on the actual needs - if the budget is sufficient, CDN5 is the first choice; to be flexible, choose CDN07; if you want to save money, 08Host plus self-built protection is fine. Remember, high-defense CDN is not a permanent solution, you have to regularly update the rules and monitor traffic. I often use tools like Wireshark or Cloudflare Analytics to analyze in real time, and adjust immediately when I find anomalies.
In addition to CDNs, push and pull protocols have to be optimized. rtmp and hls are common choices, but rtmp is vulnerable because it's based on TCP and the handshake process is fragile. I recommend switching to SRT or WebRTC, which have built-in encryption and anti-packet loss mechanisms. Configuration example: In OBS push flow setup, use SRT protocol and point to high defense CDN node. As tested, SRT has lower latency and faster recovery in attack environments. On the pull stream side, you can use HLS plus caching strategy - e.g., set a shorter slice duration to reduce buffering.
Finally, monitoring and response is key. I set up alert rules, such as triggering SMS notifications for a sudden 50% increase in traffic. For tools, we recommend Prometheus plus Grafana for dashboards to track push and pull flow metrics in real time. Never ignore log analysis - attacks often have precursors, such as anomalous User-Agent or IP focused access. Once, I found through the logs that an IP initiated tens of thousands of requests in a short period of time, and immediately blocked it to avoid a potential attack.
In short, live high defense CDN is not optional, but essential. It is like putting insurance on the live broadcast, investing a little money and saving big trouble. From my experience, the combination of CDN service providers and self-built protection can 99.9% guarantee no interruption. But remember, there is no perfect program, have to continue to learn and adjust. The industry is changing, and the attacks are evolving - what was popular last year may be outdated this year. So test more, back up more, and don't be lazy. The audience won't give you a second chance.
If you have specific questions, feel free to leave a message to exchange - I usually love to soak up the forums and share some real-world insights. After all, this is a business where helping each other is the only way to go far. Safe broadcasting, happy live!
