How to defend against DDOS? Detailed explanation of core protection methods and skills

at the moment of rapid development of Internet business, DDOS attacks have become a common risk threatening enterprise cyber security. Such attacks crowd out server resources through massive fake traffic, causing business systems to be paralyzed and users to be unable to access normally, bringing direct economic losses and brand reputation damage to enterprises. Many enterprises are at a loss when they encounter attacks, and lack systematic defense ideas and practical operation plans. This article will dismantle the core methods and practical skills of DDOS defense from multiple levels such as architecture optimization, traffic identification, and emergency response to help enterprises build a full range of protective barriers.

First, the defense of DDOS needs to optimize the basic network architecture

solid basic network architecture is the premise of defense against DDOS, and reasonable architecture design can reduce the impact of attacks from the source and avoid total paralysis caused by single point of failure.

1, build a multi-node redundant architecture

enterprises should abandon the single-server deployment model and adopt a multi-node cluster or distributed architecture to disperse business traffic to multiple server nodes. When encountering a DDOS attack, the traffic pressure of a single node will be shared by other nodes, which will not directly lead to the release of the entire business system. At the same time, it can be combined with remote disaster recovery nodes to quickly switch to standby nodes when the main node is attacked to ensure business continuity.

2, hide the real server Internet Protocol Address

provide services through CDN acceleration services or reverse proxy servers, and hide the real server Internet Protocol Address behind the proxy layer. The target of DDOS attacks is usually directly to the server IP, and hiding the real IP allows the attack traffic to reach the proxy node first, and the proxy layer completes the preliminary traffic cleaning and filtering to reduce the risk of real servers being exposed to attacks.

two, defense DDOS to do a good job of traffic identification and accurate filtering

DDOS attack is false traffic, so accurate identification and filtering of abnormal traffic is the core of defense against DDOS, which can effectively reduce the occupation of invalid traffic on server resources.

1. Identify abnormal traffic

use professional intrusion detection systems or traffic analysis tools to monitor the characteristics of network traffic in real time, such as abnormal request frequency, high-frequency access of a single IP, and request packets that do not conform to business logic. When traffic that meets the characteristics of DDOS attacks is detected, the system can automatically trigger interception rules, discard such abnormal traffic directly, and avoid it from entering the server node.

2 Set access frequency limit rules

set a reasonable access frequency threshold for each Internet Protocol Address or user according to the normal access law of the business, such as allowing up to 100 requests per minute for a single IP. When the access frequency of an IP exceeds the threshold, the system will automatically temporarily block or verify the verification code to filter out the high-frequency false requests generated by DDOS attacks, and will not affect the access of normal users.

Third, the defense of DDOS needs to establish a sound emergency response mechanism

even if a perfect protection system is established, it is difficult to completely avoid DDOS attacks, so a set of fast and effective emergency response mechanisms can be established to minimize losses when attacks occur.

1, develop a graded response plan

according to the size of the flow of the attack, the scope of influence, the DDOS attack is divided into different levels, for each level to develop a corresponding response process. For example, mild attacks can be automatically triggered by the system protection rules, moderate attacks require operation and maintenance personnel to intervene to adjust the protection strategy, severe attacks need to start disaster recovery switching, contact operators to clean traffic and other measures to ensure that each type of attack has a clear response plan.

2, carry out regular offensive and defensive drills

enterprises should regularly organize internal or third-party attack and defense drills to simulate different types of DDOS attack scenarios and test the effectiveness of existing defense systems and the feasibility of emergency response processes. Through drills, loopholes in the protection system are found in a timely manner, and defense strategies and response processes are optimized, so that operation and maintenance personnel can quickly and accurately take countermeasures when real attacks occur.

4. Defense against DDOS can improve protection capabilities with the help of Cloud as a Service

for small and medium-sized enterprises, it is difficult to build a high-cost defense DDOS system alone. With the help of Cloud as a Service provider's professional protection services, strong protection capabilities can be obtained at a lower cost.

1, choose cloud DDOS protection service

mainstream Cloud as a Service providers provide professional DDOS protection services, which rely on the massive bandwidth and distributed protection nodes of the cloud platform to easily undertake and clean TB-level attack traffic. Enterprises only need to connect their business to cloud protection services to obtain real-time traffic monitoring, attack identification and automatic cleaning capabilities, without investing a lot of cost to build their own defense systems.

2, combined with cloud security products collaborative protection

in addition to dedicated DDOS protection services, it can also combine cloud WAF, cloud firewall and other security products to build a multi-level defense system. Cloud WAF can filter malicious requests at the application layer, and cloud firewall can intercept abnormal traffic at the network layer, complementing with DDOS protection services to further improve the overall effect of defense against DDOS and ensure the security of business systems in an all-round way.

To sum up, the defense of DDOS is a systematic project. It is necessary to start from multiple dimensions such as infrastructure optimization, traffic precision filtering, emergency response mechanism construction, and Cloud as a Service collaboration to build a multi-level protection system. Enterprises should choose appropriate protection methods according to their own business scale and security needs, and regularly optimize protection strategies in order to effectively resist various DDOS attacks and ensure the stable operation of business systems.