Summary of events
When a website encounters DDoS attacks, it is not always enough to buy some kind of high-end firewall. Ordinary cabinet bandwidth may be flooded by UDP and connection tables or application layers can also be dragged away. The defense should be layered according to the type of attack, business traffic, budget and compliance use: first hide source stations with CDN and tighten firewalls, then consider IP protection or Anycast cleaning depending on the traffic size; Application layers are handed over to WAF and speed limit checking.
Core Conclusion: DDoS defense is not a single product, but rather a layered solution. For webmasters, the goal isn't to hold onto the largest attack cluster forever, but to let common attacks go first, with medium-large traffic having cleaning paths and application layers having rules at the bottom.
What is it?
When a site is attacked by competitors, or encounters an erroneous sweeper attack, the normal machine room bandwidth can easily be flooded with UDP. At this point it is not enough to look only at the peak protection of the shell and distinguish between attack pressure points: bandwidths, connection tables, backend programs.
| Forms of attack | Main points of stress | Typical example | Webmasters commonly perceive |
|---|---|---|---|
| Traffic type | Input bandwidth | UDP Flood, amplified attack | Website downtime, full bandwidth and a lot of invalid packages in the log |
| Connection type | Server connection table | TCP Flood and SYN Flood | New connection failures, service card deaths and background process abnormalities |
| The application layer | Website programs and back-end resources | CC/HTTP flooded | Page slowing down, interface errors and requests looking like normal users |
The defense schemes can be understood in the order from near to far away.
| Defensive layers | Ways of working | Suitable for interception | Limitations |
|---|---|---|---|
| Filtering of the entrance to machinery spaces / local cleaning | Configure the ACL at the network entrance in the machine room, first filtering commonly encountered packets | Small-volume attacks, commonly known as deformed packets | Limited help after entry bandwidth is blocked |
| High resistance IP ((drag wash) | When an attack occurs, traffic is redirected to a cleaning center and filtered back to the source station. | Medium to large-scale attacks | Higher cost of billing per protected peak; quality of feedback loop affects access experience |
| Anycast distributed absorption | Anycast announces and absorbs traffic through multiple nodes globally, while near-node cleanup is common in large CDN models | High traffic attacks | Application layer fine guarding still requires WAF; improperly configured feedbacks can affect the experience when there is a feedback requirement |
| WAF / application layer protection | Identifying HTTP attributes, including speed limits and human-machine validation | CC, crawl and exploit vulnerabilities | The rules need to be tweaked, they may offend regular visitors and should be observed after coming online. |
This has a direct impact on the reader: attacks can lead to access delays, order failures, fluctuations in search queries and increased customer complaints; if the defense layer is unclear, budgets may be spent on services that look like they are protecting high peaks but are actually still being dragged down by application-level requests.
How to Choose
The following combinations are eligible for priority landing by the General Steward: (a)
- Precompiled CDN
When static sites are attached to a CDN, the source site's IP is hidden and many sweeper attacks fall flat. For budget-constrained sites, this is usually the first step in priority evaluation.
- Source firewall tightened
Only the CDN return address segment is allowed, and all other sources are rejected. Verify that real visitors have been blocked before logging in to verify whether accesses such as payback call or backend login were blocked by mistake.
- Program layer speed limit
Login, search and comment interface with verification code and frequency limits to mitigate application layer attacks. Dynamic interfaces are more susceptible to CC/HTTP Flood than static pages, the speed limit threshold needs to be observed and tightened afterwards
- Monitoring the police
There is no monitoring, and it's easy to realize that an attack has been ongoing only after a user complains.
- Business volume and consideration of high-security services
If a site is down for an extended period of time or the business cannot withstand disruption, evaluate entry options such as high-protected IP, independent cleaning services, or cleanup capabilities.
Select by scene: [Selected by Scene] (scenario) *
| The scene | Prioritized configuration | Required confirmation |
|---|---|---|
| Blogs, static sites and show pages | Forward CDN, source firewall tightened | Whether the source station IP is hidden, whether the return-source address field is accurate, and whether caching rules apply |
| Foreign exchange offices, forms and sign-in systems | CDN + WAF + program layered speed | HTTP speed threshold, validation code trigger conditions and observation cycle after a normal visitor is misled |
| Big business, vulnerable to repeated attacks | High IP protection / independent cleaning | Protection of peaks, over-peak handling, cleaning triggers, feedback lines and billing |
This page does not list specific prices; the information is for 2026-10. The parameters and prices of each high-defense product vary greatly, so that they cannot be directly compared horizontally according to the same standard.
Notes and notes
Before purchasing a high-security service, it is advisable to ask questions and not just look at the security numbers on promotional pages.
- Protection against peak and over-peak processing: Is the claimed Gbps a guarantee that you're going to do your best or are you just doing your best? Are there black holes, speed limits, or upgrade fees after exceeding peaks?
- Cleaning triggers and feedback lines: Is there any business interruption during the pull? Does the feedback follow a high-quality line? Will the return address change?
- How are the costs of frequent attacks accumulated?
- Does application-level protection cost extra: does it support custom rules? Can the CC, crawl and exploit rules be adjusted?
- Compliance use: The server and defense services are used only for legitimate purposes such as site construction, development testing, foreign trade operations.
Conclusion: There is no fixed answer to the defense plan, parameters, routes, triggering methods and billing are based on official publications; verification of information for 2026-10.
FAQs
1. Is a CDN alone enough?
For static sites and common sweep attacks, a CDN can hide the source station and absorb part of the traffic. However, dynamic interfaces, login pages, search pages may still be dragged by CC/HTTP Flood requiring WAF, authentication code, frequency limitation support.
2. Is a high IP better than an ordinary machine room?
Not necessarily. High-Defense IP is suitable for medium to high traffic attacks, but the cost, protection peak, superpeak processing and feedback line quality will all affect the experience. Under low-traffic or application layer attacks, a single high-defence IP does not have to solve every problem.
3. Can Anycast protect against all attacks?
Anycast can disperse traffic to multiple nodes near the cleaning, suitable for ultra-large traffic scenarios. But application layer fine protection is still required WAF; if wrong configuration of feedbacks, normal users may also experience slow connection, overtime or geographical access instability .
4. When the firewall is tightened, what are some of the most vulnerable holes?
A common pitfall is releasing only a portion of the CDN's return address, or forgetting to retain backend, redirect and monitor portals. Before tightening, first clean up the source IP segment and prepare for fast rollback schemes.
5. What should be considered when attacks are frequent?
Retain samples of monitoring alerts, traffic logs, firewall interceptions and application layer requests. Confirm with the service provider that cleaning triggers are protected against peak or off-peak processing and billing methods to avoid repeated replacement schemes when information is insufficient
Links within the site
- How to choose an overseas server machine line
- Configuration guide for VPS firewalls and source stations
- Performance and stability checklist of foreign trade stations
- Comparison of DDoS protection services from standalone servers
- Develop and test environmental safety baselines
Updated with pictures
This article was last updated on 01/10/2016.
This post is part of our special coverage Africa Day.
- The entrance of the engine room is filtered with a high protection IP filtering clean gesture, no text, no brand logo and no real person
- 3D CDN, WAF, firewall layered defense signage, no text, no brand logo and no real people.
- The map node and Anycast are close to clean gestures, no text, no branded logos, no real people
Reader comments (0)