Skip to content

Míchel Redondo#

VLANs on SR Linux and Arista/Cisco

In the recent VLANs on SR Linux blog post we dived deep into the world of VLANs on SR Linux where we saw that VLAN handling in SR Linux is not quite like what we used to see on Cisco/Arista systems.

As a sequel to the original post we decided to mix SR Linux with another popular Network OS - Arista EOS. By mixing different vendor implementations we wanted to provide clear guidance on how to interop between distinct VLAN implementations and help new SR Linux to map existing VLAN concepts to the SR Linux model.


Exposing Kubernetes Services to SR Linux-based IP Fabric with Anycast Gateway and MetalLB

In the era of applications, it is easy to forget about the underlying infrastructure that interconnects them. However, the network is still the foundation of any application as it provides the connectivity and services that applications rely on.

The most popular container orchestration system - Kubernetes - is no exception to this rule where infrastructure is essential for several reasons:

  1. DC fabric: Almost every k8s cluster leverages a DC fabric underneath to interconnect worker nodes.
  2. Communication Between Services: Kubernetes applications are often composed of multiple microservices that need to communicate with each other. A well-designed network infrastructure ensures reliable and efficient communication between these services, contributing to overall application performance.
  3. Load Balancing: Kubernetes distributes incoming traffic across multiple instances of an application for improved availability and responsiveness. A robust network setup provides load balancing capabilities, preventing overload on specific instances and maintaining a smooth user experience.
  4. Scalability and Resilience: Kubernetes is renowned for scaling applications up or down based on demand. A resilient network infrastructure supports this scalability by efficiently routing traffic and maintaining service availability even during high traffic periods.

Getting familiar with all these features is vital for any network engineer working with a fabric supporting a k8s cluster. Wouldn't it be great to have a way to get into all of this without the need of a physical lab?

In this blog post we will dive into a lab topology that serves as a virtual environment to test the integration of a Kubernetes cluster with an IP fabric. The emulated fabric topology consists of a SR Linux-based Clos fabric with the Kubernetes cluster nodes connected to it. The k8s cluster features a MetalLB load-balancer that unlocks the capability of announcing deployed services to the IP fabric.

Throughout the lab, we will explore the way k8s services are announced to the IP fabric, and how L3 EVPN service with Anycast Gateway can be leveraged to create a simple and efficient overlay network for external users of the k8s services.

As for the tooling used to bring up the lab we will use Minikube to deploy a personal virtual k8s cluster and Containerlab will handle the IP fabric emulation and the connection between both environments.