Virtual networking labs – building a virtual router with iptables and Linux namespaces

When you are trying to understand virtual networking, container networks, micro segmentation and all this, sooner or later the day will come where you will have to deal with iptables, the built-in Linux firewall mechanism. After evading the confrontation with the full complexity of this remarkable beast for many years, I have recently decided to … Continue reading Virtual networking labs – building a virtual router with iptables and Linux namespaces

Virtual networking labs – more on bridges

In the previous post, we have seen how a software-defined Linux bridge can be established and how it transparently connects two Ethernet devices. In this post, we will take a closer look at how to set up and monitor bridges and learn how VirtualBox uses bridges for virtual networking. Lab 6: setting up and monitoring … Continue reading Virtual networking labs – more on bridges

Virtual networking labs – VirtualBox internal networks and bridges

So far, we have been playing with virtual networking for one virtual machine, connected to the host. Now let us see how we can establish virtual networks connecting more than one machine. Lab3: Virtualbox host-only networking with more than one machine In this lab, we will connect two virtual machines that both use host-only networking. … Continue reading Virtual networking labs – VirtualBox internal networks and bridges

Managing traffic with Kubernetes ingress controllers

In one of the previous posts, we have learned how to expose arbitrary ports to the outside world using services and load balancers. However, we also found that this is not very efficient - in the worst case, the number of load balancers we need equals the number of services. Specifically for HTTP/HTTPS traffic, there … Continue reading Managing traffic with Kubernetes ingress controllers

Watching Kubernetes networking in action

In this post, we will look in some more detail into networking in a Kubernetes cluster. Even though the Kubernetes networking model is independent of the underlying cloud provider, the actual implementation does of course depend on the cloud provider which communicates with Kubernetes through a CNI plugin. I will continue to use EKS, so … Continue reading Watching Kubernetes networking in action