DDoS (Distributed Denial of Service) Attacks pose significant threats to organizations and individuals by overwhelming targeted systems, services, or networks with excessive traffic. This flood of internet traffic can make websites, online services, and networks inoperable, leading to downtime, loss of revenue, and potential damage to an organization's reputation. DDoS attacks can also serve as a cover for more serious cyber threats, such as data breaches or malware infection.
Given these risks, it's crucial to defend against DDoS attacks. Protecting against such attacks ensures the continuity of business operations, safeguards data integrity, and maintains customer trust and confidence. Effective defense strategies involve a combination of robust security infrastructure, including specialized DDoS protection tools and services, along with a comprehensive understanding of DDoS attack patterns and methodologies.
What is the Key to Mitigating DDoS Attacks?
Mitigating DDoS attacks is about distinguishing between attack traffic and normal traffic. This involves implementing various techniques and tools to identify and filter out malicious traffic while allowing legitimate users to access the services without interruption.
When a company's website suddenly gets a lot more visitors because of a new app release and the load on the website goes up a lot, it might be because of a DDoS attack. In that case, it wouldn't be a good idea to block all traffic. If the company notices a big increase in traffic from users they know are malicious, they might have to take action to stop the attack. The tricky part is figuring out the difference between real customer traffic and attack traffic.
In today's internet, DDoS attacks come in various forms. The design of the traffic can vary, from straightforward single-source attacks to complex adaptive multi-directional attacks. Multi-directional DDoS attacks employ different methods to disrupt targets, often diverting mitigation efforts at all levels. For instance, a multi-directional DDoS attack may target multiple levels of the protocol stack, such as DNS amplification (targeting layers 3/4) combined with an HTTP flood (targeting layer 7). To protect against multi-directional DDoS attacks, it's necessary to utilize multiple strategies to mitigate attacks at different levels. Generally, the more intricate the attack, the more difficult it becomes to differentiate between attack traffic and normal traffic. Attackers aim to blend in with normal traffic as much as possible, reducing the effectiveness of mitigation. If mitigation measures indiscriminately discard or limit traffic, they may discard normal traffic along with attack traffic, and the attack may also be adjusted to evade mitigation measures. A layered solution is the ideal approach to counter complex destructive methods.
How to Defend Against DDoS Attacks?
Defending against DDoS attacks requires a variety of measures, we can consider the following:
Blackhole Routing
Blackhole routing is a method used to counter Distributed Denial of Service (DDoS) attacks. During a DDoS attack, a large volume of malicious traffic is directed at a network or server, which overwhelms the system and prevents it from responding to legitimate user requests. Blackhole routing works by rerouting all traffic intended for the targeted system to a "black hole" network address. Any traffic sent to this address is discarded without a response. The aim is to stop the malicious traffic from reaching the target server, thus safeguarding it from the attack.
Implementing blackhole routing usually involves the following steps:
- Detecting the attack: First, there needs to be a mechanism to detect the occurrence of a DDoS attack.
- Triggering blackhole routing: Once an attack is detected, the network administrator can manually or automatically trigger blackhole routing.
- Broadcasting routing updates: By using BGP (Border Gateway Protocol) or other routing protocols, update the routing table to tell all routers to redirect traffic from the target IP address to the black hole.
- Traffic discard: All traffic sent to the attacked IP address will be routed to the black hole and discarded there.
Even though blackhole routing can effectively reduce the impact of malicious traffic on the target system, it has a significant drawback: legitimate traffic is also discarded. This means that during an attack, the affected service is unavailable to all users. Therefore, blackhole routing is often seen as a last-resort defense measure. In some cases, more refined methods may be used, such as "Scrubbing Centers" or other types of traffic analysis and filtering, to distinguish and block malicious traffic while allowing legitimate traffic to pass.
Rate Limiting
Rate Limiting is a technique used to control the amount of incoming and outgoing traffic to or from a network. It works by setting a limit on the number of requests a user can make to a server within a specified time frame. This helps prevent DDoS (Distributed Denial of Service) attacks by ensuring that no single user or group of users can overwhelm the server with excessive requests, thereby maintaining the server's availability and performance. By implementing rate limiting, servers can effectively manage traffic loads and mitigate the risk of being taken offline by malicious actors.
Web Application Firewall
A Web Application Firewall (WAF) is a security system that monitors, filters, and blocks HTTP/HTTPS traffic to and from a web application. It operates by inspecting incoming requests and outgoing responses based on a set of predefined security rules. These rules are designed to identify and block malicious traffic, such as SQL injection, cross-site scripting (XSS), and other web-based attacks.
WAF can preventing DDoS (Distributed Denial of Service) attacks in the following ways:
- Filtering Malicious Traffic: A WAF can detect and block traffic patterns indicative of a DDoS attack, such as a sudden surge in requests from a single IP address or a group of IP addresses.
- Rate Limiting: Many WAFs include rate limiting features that restrict the number of requests a user can make in a given period, thereby preventing any single user or group of users from overwhelming the server.
- Bot Mitigation: WAFs can identify and block traffic from known malicious bots and automated scripts often used in DDoS attacks.
- Traffic Anomaly Detection: Advanced WAFs use machine learning and behavioral analysis to detect unusual traffic patterns that may indicate a DDoS attack, allowing for real-time response and mitigation.
Deploying Reverse Proxies and Load Balancers
Reverse proxy servers and load balancers can help enterprises distribute DDoS attack traffic to multiple servers, thereby reducing the impact of the attack. Specific methods include:
- Deploying reverse proxy servers: Reverse proxy servers are located between the enterprise's internal network and the Internet and can forward requests from external sources to internal servers. When an enterprise is hit by a DDoS attack, reverse proxy servers can distribute traffic to multiple internal servers, thereby reducing the impact of the attack.
- Deploying load balancers: Load balancers can distribute traffic to multiple servers, thereby reducing the load on a single server. When an enterprise is hit by a DDoS attack, load balancers can distribute traffic to multiple servers, thereby reducing the impact of the attack.
Using Cloud Protection
Cloud protection can help enterprises defend against DDoS attacks in the cloud, reducing the impact of the attack. Specific methods include:
- Choosing reliable cloud protection service providers: Enterprises can choose reliable cloud protection service providers to guide network traffic to the cloud for defense.
- Using cloud protection devices: Cloud protection devices can filter out DDoS attack traffic, thereby reducing the impact of the attack.
- Deploying cloud protection nodes: Enterprises can deploy cloud protection nodes to distribute traffic to multiple nodes, thereby reducing the impact of the attack.
Strengthening Network Monitoring
Enterprises should strengthen network monitoring, monitor network traffic and server status in real-time, and respond to DDoS attacks promptly. Specific methods include:
- Using network traffic monitoring tools: Network traffic monitoring tools can monitor network traffic in real-time and detect DDoS attacks promptly.
- Using server monitoring tools: Server monitoring tools can monitor server status in real-time and detect when a server is hit by a DDoS attack.
- Deploying intrusion detection systems (IDS) and intrusion prevention systems (IPS): IDS and IPS can detect and respond to DDoS attacks promptly.
Strengthening Server Security
Enterprises should strengthen server security, including using strong passwords, regularly updating and upgrading systems and software, disabling unnecessary services, etc., to reduce the likelihood of servers being attacked. Specific methods include:
- Using strong passwords: Enterprises should use strong passwords to protect their servers and accounts.
- Regularly updating and upgrading systems and software: Enterprises should regularly update and upgrade their systems and software to fix vulnerabilities and improve security.
- Disabling unnecessary services: Enterprises should disable unnecessary services on their servers to reduce the attack surface and minimize the impact of DDoS attacks.
Conclusion
Tencent EdgeOne offers robust DDoS protection, leveraging Tencent's extensive global network and advanced security technologies.
Tencent EdgeOne DDos Protection provides the following features:
- Traffic Monitoring and Detection: The service continuously monitors network traffic and detects abnormal traffic patterns that may indicate a DDoS attack.
- Automatic Mitigation: Once an attack is detected, Tencent EdgeOne DDoS Protection automatically triggers mitigation measures to block the malicious traffic and protect the targeted system.
- Real-time Reporting: The service provides real-time reports on attack traffic, including the source IP addresses, attack types, and other relevant information.
- Customizable Protection Policies: Users can customize protection policies based on their specific needs, such as setting up whitelist and blacklist rules, adjusting traffic thresholds, and more.
- Global Coverage: Tencent EdgeOne DDoS Protection leverages Tencent's global network infrastructure to protect users worldwide.
By using Tencent EdgeOne DDos Protection, businesses can ensure the availability and performance of their online services, even in the face of large-scale DDoS attacks. We have now launched a free trial, welcome to contact us for more information.