L7 DDoS protection is a term for protecting against application layer attacks. These attacks are often called application layer DDoS attacks, and are one of the most dangerous types of DDoS attacks. Application layer DDoS attacks can range from attacks on vulnerabilities in TCP protocol to flooding servers with attack traffic.
The first line of defense against application layer DDoS attacks is firewalls and other similar filtering technologies.
In order to identify a L7 DDoS attack, we need to understand the difference between HTTP, TCP and UDP traffic.
HTTP is an application layer protocol. TCP and UDP are transport layer protocols.
A Layer 7 DDoS attack usually targets the TCP or UDP protocol and it is very difficult to distinguish between HTTP and TCP/UDP traffic.
L7 DDoS Defense Strategies
As easy as they are to perpetrate, Layer 7 attacks are notoriously difficult to mitigate. These attacks are often not detected before it’s too late because they emulate legitimate human user behavior.
Unlike network layer attacks, Layer 7 attacks can’t be mitigated only by the strength of your network capacity. Instead, companies typically rely on web application firewalls (WAFs), manual IP filtering, and ad-hoc network analysis. The problem with these approaches is twofold:
- Hackers can now easily distribute bots via hundreds of thousands of different IP addresses, making IP-based filtering largely ineffective
- Manual filtering is very resource-consuming and generally too slow to efficiently mitigate large attacks.
The most effective way by far to protect your applications against L7 DDoS attacks is to accurately profile your incoming traffic. This will enable you to distinguish bots from humans, and to block any unwanted or suspicious traffic without disturbing the user experience for your intended audiences.
The application layer protocol is the level of communication between a web browser and web server. Attacks on this layer typically take the form of injections of malicious code into the data stream, or by interfering with the connection itself. The term for protecting against these attacks is called DDoS protection.