TL;DR
DDoS protection at the edge reduces volumetric and network-based attack pressure before it reaches a company's public infrastructure. Scrubbing thus protects the entry to applications and APIs. However, it does not replace backend security, authentication, resource limits, or domain-specific checks against misuse.
Introduction
DDoS protection often fails not due to a lack of filtering capability, but due to an incorrect delineation of protection layers. An attack can be effectively mitigated at the network edge and still exhaust backend resources if each valid request triggers extensive processing. Conversely, a backend is hardly capable of economically and stably processing large amounts of unwanted traffic on its own. The central architectural decision is therefore not "Edge or Backend," but: What type of load is recognized and handled at which point? DDoS Protection and Scrubbing at the edge primarily address the public entry point. Authentication, authorization, and domain-specific misuse remain tasks of the application.
1. What DDoS Protection at the Edge Can Achieve
A DDoS attack often initially targets availability: lines, network components, load balancers, or servers are to be impaired by high request or packet volumes. An edge platform can intercept this pressure before the actual backends are reached. DDoS Protection and Scrubbing analyze incoming traffic and filter out unwanted patterns as close to the public entry as possible.
In a distributed edge architecture, traffic is not first routed to a single location. The ayedo Edge Cloud uses an Anycast-based, distributed infrastructure with its own Autonomous System and active-active principle. This is not proof that every attack is automatically resolved. However, it creates an architecture where protection and routing functions are positioned in front of the backends and do not solely depend on their own capacity.
2. Why Scrubbing Protects the Public Entry
Scrubbing fulfills a different task than a security mechanism within the application. The goal is to remove harmful or unwanted traffic from the data stream before it burdens network paths and resources of the backend environment. This particularly concerns volumetric attacks as well as certain network or protocol-related loads.
The effect arises from the position of the protection function. When DNS, routing, load balancing, and DDoS defense work together at the edge, the public entry of applications and APIs remains under central control. The backends then do not have to accept and process every incoming connection themselves. Backend Cloaking reinforces this separation: the actual origin addresses do not have to be publicly visible as direct attack points.
This architecture reduces the attack surface but does not eliminate it. Even after scrubbing, legitimate requests continue. For these, the backend must still provide sufficient capacity, appropriate timeouts, and controlled processing.
3. Where Edge Protection Reaches Its Limits
Not every harmful request is recognizable as an attack at the network level. An attacker can establish valid TCP connections, send correct HTTP requests, and even successfully authenticate. Technically, the traffic initially appears as regular usage. DDoS protection at the edge cannot reliably assess such requests based on their domain-specific intent.
The next limit lies in resource exhaustion through expensive operations. A single valid API request can, for example, trigger database queries, external calls, or complex calculations. If such requests are made in large numbers, an application-layer problem arises. Protection mechanisms such as rate limits, quotas, concurrency limits, caching, backpressure, and targeted contingents must intervene where the domain-specific significance is known.
Authentication and authorization also remain backend tasks. The edge can protect the entry and secure HTTP/HTTPS services via a WAF. However, it does not automatically decide whether an authenticated user is misusing a particular resource.
4. Backend Security as a Second Layer of Protection
Backend security begins with the assumption that edge protection does not replace a trust boundary for the application. Applications must verify incoming identities, permissions, and input parameters themselves. Additionally, they should limit resources per user, tenant, API key, or client. This prevents a valid access from triggering uncontrolled large amounts of processing.
For operations, measurable protection boundaries are crucial: maximum request duration, queue size, connection limits, error rates, and controlled abort conditions. Health checks and failover help to remove unavailable backends from the traffic. However, they do not prevent domain-specific valid but harmful requests. If a backend is distributed across multiple clusters or providers, the edge can route and distribute public traffic independently of the provider. The security logic within these targets must still be consistently implemented.
Economically, the separation is also relevant. Edge scrubbing can prevent unnecessary traffic from consuming expensive network and compute resources. Investments in application protection remain necessary because a smaller but domain-specific costly attack can still generate costs and operational risks.
Practical and Operational Scenario
A company operates a public API on its own Kubernetes cluster. A volumetric attack generates large amounts of unwanted packets and HTTP requests. Without a preceding edge protection layer, the cluster, ingress, and provider connection must at least partially absorb the attack traffic. With DDoS Protection and Scrubbing at the ayedo Edge Cloud, the public entry is protected before the backend; only scrubbed traffic is forwarded.
Later, an attacker uses valid credentials to repeatedly invoke a costly search function. This traffic is domain-specifically plausible and passes the edge. Only rate limits per identity, a request budget, and a limitation of parallel search operations in the backend prevent resource exhaustion. Both protection layers solve different problems.
FAQ
Does DDoS protection at the edge automatically protect every API application?
No. It primarily reduces unwanted traffic at the public entry. Authentication, authorization, rate limits, and domain-specific misuse rules must still be implemented in the API and backend.
What is the difference between scrubbing and a WAF?
Scrubbing primarily addresses harmful or excessive traffic at the network and transport level. A WAF examines HTTP/HTTPS requests and can filter application-specific attack patterns. Both functions are positioned before the backend but pursue different protection tasks.
Is backend security sufficient without edge protection?
Possibly for small attacks, but rarely as a reliable architecture. The backend must first reach and process the traffic. Edge protection reduces this preliminary load; the application still requires its own security and limitation mechanisms.
Conclusion
DDoS protection at the edge and backend security are not competing measures. The edge protects the public entry, filters volumetric pressure, and keeps unwanted traffic as far away from network and compute resources as possible. The backend, on the other hand, evaluates identities, permissions, and the domain-specific costs of a request. The ayedo Edge Cloud is in this model the upstream, distributed protection and routing platform; its effect arises in conjunction with robust boundaries within the applications.