Azure Kubernetes Fleet Manager’s Cross-Cluster Networking Feature Now in Public Preview

Microsoft Azure has announced the public preview of Azure Kubernetes Fleet Manager’s Cross-Cluster Networking feature, which provides seamless networking capabilities between multiple Kubernetes clusters. This feature is based on Advanced Container Networking Services and achieves transparent East-West multi-cluster networking using Cilium.

In traditional multi-cluster environments, communication between multiple Azure Kubernetes Service (AKS) clusters required complex VPNs or gateways. The new feature allows platform teams to abstract infrastructure details from developers, enabling cluster-level changes without disrupting applications.

(Source: Azure Blog)

Solving Multi-Cluster Networking Challenges

Due to regulatory requirements, regional disaster recovery, or fault domain isolation, organizations of all sizes operate multiple AKS clusters. However, managing these clusters has traditionally been subject to the “networking tax”.

Conventional approaches relied on complex VPNs, gateways, and manual service discovery, increasing latency and operational complexity. Especially for large-scale cluster fleets, teams need consistent, reliable cross-cluster connections to support failover, shared service architectures, and seamless workload migration across regions for capacity and latency.

(Source: Azure Blog)

High-Performance Networking Implementation Based on Cilium

Azure Kubernetes Fleet Manager is designed to address multi-cluster management. The new cross-cluster networking feature provides a managed, high-performance network based on Cilium, which can span across the entire fleet.

This implementation enables consistent, reliable cross-cluster connections from a few clusters to large-scale cluster fleets. Platform teams can abstract infrastructure details, allowing developers to make cluster-level changes seamlessly without disrupting applications.

(Source: Azure Blog)

Getting Started with Implementation

To try Azure Kubernetes Fleet Manager’s cross-cluster networking feature, start with the official documentation from Microsoft Learn. As it is in the public preview stage, thorough validation is recommended before using it in production environments.

You can also find an overview of Advanced Container Networking Services in Azure’s official documentation, which includes setup procedures, limitations, and best practices.

(Source: Azure Blog)

Summary

  • Azure Kubernetes Fleet Manager’s cross-cluster networking feature enables direct communication between multiple AKS clusters without VPNs or complex gateway settings
  • The Cilium-based implementation eliminates the traditional “networking tax”, reducing latency and operational complexity
  • By leveraging Advanced Container Networking Services, you can achieve consistent, high-performance networking even in large-scale cluster fleets
  • Start with Microsoft Learn’s official documentation to begin setup and validate the new approach to multi-cluster management in the public preview environment