Any network device, be it a transit router or a host, usually has multiple IP addresses assigned to its interfaces. One of the first things we learn as network engineers is how to determine which IP address is used for the locally-sourced traffic. However, the default scenario ca … | Continue reading
In the previous post, I mentioned that CUE can help you work with both “industry-standard” semi-structured APIs and fully structured APIs where data is modelled using OpenAPI or JSON schema. However, there was an elephant in the room that I conveniently ignored but without which … | Continue reading
What I’ve covered in the previous blog post about CUE and Ansible were isolated use cases, disconnected islands in the sea of network automation. The idea behind that was to simplify the introduction of CUE into existing network automation workflows. However, this does not mean C … | Continue reading
Hardly any conversation about network automation that happens these days can avoid the topic of automation frameworks. Amongst the few that are still actively developed, Ansible is by far the most popular choice. Ansible ecosystem has been growing rapidly over the last few years, … | Continue reading
In the past few years, network automation has made its way from a new and fancy way of configuring devices to a well-recognized industry practice. What started as a series of “hello world” examples has evolved into an entire discipline with books, professional certifications and … | Continue reading
In one of his recent posts, Ivan raises a question: “I can’t grasp why Cumulus releases a Vagrant box, but not a Docker container”. Coincidentally, only a few weeks before that I had managed to create a Cumulus Linux container image. Since then, I’ve done a lot of testing and dis … | Continue reading
eBPF has a thriving ecosystem with a plethora of educational resources both on the subject of eBPF itself and its various application, including XDP. Where it becomes confusing is when it comes to the choice of libraries and tools to interact with and orchestrate eBPF. Here you h … | Continue reading
When using a personal VPN at home, one of the biggest problems I’ve faced was the inability to access public streaming services. I don’t care about watching Netflix from another country, I just want to be able to use my local internet connection for this kind of traffic while sti … | Continue reading
There comes a time in the life of every Kubernetes cluster when internal resources (pods, deployments) need to be exposed to the outside world. Doing so from a pure IP connectivity perspective is relatively easy as most of the constructs come baked-in (e.g. NodePort-type Services … | Continue reading
Every Kubernetes cluster is provisioned with a special service that provides a way for internal applications to talk to the API server. However, unlike the rest of the components that get spun up by default, you won’t find the definition of this service in any of the static manif … | Continue reading
Last week I posted a tweet about a Kubernetes networking puzzle. In this post, we’ll go over the details of this puzzle and uncover the true cause and motive of the misbehaving ingress.Puzzle recap Imagine you have a Kubernetes cluster with three namespaces, each with its own nam … | Continue reading
Cluster API (CAPI) is a relatively new project aimed at deploying Kubernetes clusters using a declarative API (think YAML). The official documentation (a.k.a. the Cluster API book), does a very good job explaining the main concepts and goals of the project. I always find that one … | Continue reading
In September 2019 I had the honour to present at Open Networking Summit in Antwerp. My talk was about meshnet CNI plugin, k8s-topo orchestrator and how to use them for large-scale network simulations in Kubernetes. During the same conference, I attended a talk about Network Servi … | Continue reading
In the previous two posts, we’ve seen how to build a custom network API with Kubernetes CRDs and push the resulting configuration to network devices. In this post, we’ll apply the final touches by enabling oAuth2 authentication and enforcing separation between different tenants. … | Continue reading
In the previous post, we’ve examined the foundation of the Network-as-a-Service platform. A couple of services were used to build the configuration from data models and templates and push it to network devices using Nornir and Napalm. In this post, we’ll focus on the user-facing … | Continue reading
Recently I’ve been pondering the idea of cloud-like method of consumption of traditional (physical) networks. My main premise for this was that users of a network don’t have to wait hours or days for their services to be provisioned when all that’s required is a simple change of … | Continue reading
Every time when I get bored from my day job I tend to find some small interesting project that I can do that can give me an instant sense of accomplishment and as the result lift my spirits and improve motivation. So this time I remembered when someone once asked me if they could … | Continue reading
In the previous post I’ve demonstrated how to build virtual network topologies on top of Kubernetes with the help of meshnet-cni plugin. As an example, I’ve shown topologies with 50 cEOS instances and 250 Quagga nodes. In both of these examples virtual network devices were runnin … | Continue reading