Clearly Separate DNS Control and Anycast Routing

TL;DR

DNS answers the question of which address a service is reachable at. Anycast routing determines to which network location packets are directed. Only there do Layer-4 or Layer-7 load balancers distribute connections and requests to backends. A robust edge architecture separates these layers but connects them in a controlled manner.

Introduction

A common architectural mistake is to treat DNS as the actual traffic control. Changing a DNS entry does not automatically redirect every existing connection or distribute the load within a service. DNS provides name resolution; routing ensures reachability; load balancing decides on the distribution of incoming connections or HTTP requests. These differences are crucial for failover, security, and operations. The ayedo Edge Cloud combines authoritative DNS functions, Anycast network access, and Layer-4 or Layer-7 load balancing in one platform. The functions fulfill different tasks and should also be planned separately.

1. DNS Answers a Different Question Than Routing

Authoritative DNS manages the assignment of a name to DNS resource records. For example, a resolver queries which address api.example.com is reachable at. The answer is cached depending on TTL and resolver behavior. Thus, a DNS change is not immediately effective for every client. Already established TCP or TLS connections remain as long as they function.

DNS control can select endpoints, such as between different IP addresses or service variants. However, it does not automatically know the state of each individual connection and does not distribute HTTP requests like a Layer-7 proxy. Even a low TTL value does not make DNS a real-time traffic management mechanism. It merely reduces the possible cache duration.

For architecture, this means: DNS defines the public name and the resulting reachability information. It is a control plane for name resolution, not the data path decision for each request. In the ayedo Edge Cloud, Anycast DNS and Multi-Provider DNS belong to this upstream layer.

2. Anycast Routing Determines the Network Path

With Anycast, the same IP address is announced from multiple network locations. Internet routing typically directs packets to the most network-appropriate reachable location. This selection is based on routing information and network topology, not on the content of an HTTP request or the current state of individual backend instances.

Anycast routing thus answers the question: At which edge location should network traffic enter the platform? It neither replaces DNS nor a load balancer. If a location or service path fails, the announcement can be adjusted so that traffic uses another reachable location. How quickly and to what extent this change becomes effective depends on the routing and the networks involved.

For operations, Anycast creates a distributed entry point. The ayedo Edge Cloud uses its own network infrastructure and its own Autonomous System in a distributed Multi-PoP architecture. The active-active principle allows incoming traffic to be accepted over multiple active edge locations, rather than planning a single central entry as a mandatory bottleneck.

3. Load Balancing Distributes Connections and Requests

When a packet reaches an edge location, another decision layer begins. Layer-4 load balancing operates at the transport level and distributes, for example, TCP or UDP connections to suitable backends. Layer-7 load balancing can additionally evaluate information such as hostname, path, or headers for HTTP and HTTPS traffic. This allows requests within a service to be routed more precisely than with DNS.

This distribution is state- and service-related. Backend health checks can detect if a target is reachable. Failover mechanisms then prevent new connections from going to an unavailable backend. TLS termination at the edge and a web application firewall are also on the edge processing level, not in DNS.

The separation has direct security and operational consequences. With backend cloaking, internal target addresses remain shielded from public access. Proxy Protocol can pass relevant connection information to backends without exposing the public entry point. In the ayedo Edge Cloud, these functions are bundled in front of the actual workloads, regardless of whether the backends run in ayedo Managed Kubernetes , a private Kubernetes cluster, or with another provider.

4. The Layers Must Work Together but Remain Separate

A robust architecture models DNS, routing, and load balancing as a chain with different responsibilities. DNS publishes the service name and points to the public entry point. Anycast routing brings the traffic to an available edge location. Layer-4 or Layer-7 load balancing then distributes it to suitable backends. Health checks and failover influence backend selection without needing DNS entries to be adjusted for every state change.

This division reduces operational coupling. DNS can remain stable while backends, clusters, or providers change. At the same time, the public endpoint remains independent of a single compute environment. This is relevant for migrations, multi-cloud scenarios, and Kubernetes operations across provider boundaries.

For digital sovereignty, control over DNS is not the only decisive factor. Equally relevant is control over public IP reachability, routing, protection functions, and the transition to the backends. The ayedo Edge Cloud bundles these areas of responsibility as an edge platform and also supports Bring Your Own IP. DNS thus does not become a load balancer; it remains a clearly defined but integrated control layer.

Practical and Architectural Scenario

A company operates an API in two Kubernetes clusters with different providers. Both clusters are addressed via the same public service name. With a separate DNS solution, the company would have to consider TTLs, caches, and failover behavior for changes to target addresses. Existing connections would not be captured.

With an Anycast entry point, the DNS name remains stable. Routing directs clients to a reachable edge location; there, health checks examine the backends. A Layer-7 load balancer can distribute API requests to the available clusters based on defined rules. If a backend fails, the response occurs at the load balancing level. DNS remains responsible for name resolution instead of being misused as a delayed substitute for backend failover.

FAQ

Can DNS Handle Backend Failover?

DNS can publish alternative addresses. However, due to caching, TTLs, and existing connections, it is not a precise mechanism for the immediate distribution or switching of individual connections.

Is Anycast Automatically a Load Balancer?

No. Anycast determines the network path to an edge location. The distribution to backends is then carried out by Layer-4 or Layer-7 load balancing.

Why Plan DNS and Anycast Together?

DNS defines the public service name, Anycast its reachable network entry. Joint planning prevents conflicting responsibilities and facilitates failover and provider changes.

Conclusion

DNS and Anycast routing solve different problems: DNS publishes reachability information, Anycast determines the entry path, and load balancing distributes traffic to services. Mixing these layers builds failover and operational logic on a mechanism not designed for it. The ayedo Edge Cloud combines the functions in one platform without dissolving their responsibilities. This separation creates a robust foundation for provider-independent backends and distributed edge architectures.