OpenStack Neutron – DHCP and DNS

In a cloud environment, a virtual instance typically uses a DHCP server to receive its assigned IP address and DNS services to resolve IP addresses. In this post, we will look at how these services are realized in our OpenStack playground environment. DHCP basics To understand what follows, it is helpful to quickly recap the … Continue reading OpenStack Neutron – DHCP and DNS

OpenStack Neutron – building virtual routers

In a previous post, we have set up an environment with a flat network (connected to the outside world, in this case to our lab host). In a typical environment, such a network is combined with several internal virtual networks, connected by a router. Today, we will see how an OpenStack router can be used … Continue reading OpenStack Neutron – building virtual routers

OpenStack Neutron – running Neutron with a separate network node

So far, our OpenStack control plane setup was rather simple - we had a couple of compute nodes, and all other services were running on the same controller node. In practice, this does not only create a single point of failure, but also a fairly high traffic on the network interfaces. In this post, we … Continue reading OpenStack Neutron – running Neutron with a separate network node

OpenStack Neutron – building VXLAN overlay networks with OVS

In this post, we will learn how to set up VXLAN overlay networks as tenant networks in Neutron and explore the resulting configuration on our compute nodes. Tenant networks The networks that we have used so far have been provider networks - they have been created by an administrator, specifying the link to the physical … Continue reading OpenStack Neutron – building VXLAN overlay networks with OVS

OpenStack Neutron – deep dive into flat and VLAN networks

Having installed Neutron in my last post, we will now analyze flat networks and VLAN networks in detail and see how Neutron actually realizes virtual Ethernet networks. This will also provide the basic understanding that we need for more complex network types in future posts. Setup To follow this post, I recommend to repeat the … Continue reading OpenStack Neutron – deep dive into flat and VLAN networks

OpenStack Neutron – architecture and overview

In this post, which is part of our series on OpenStack, we will start to investigate OpenStack Neutron - the OpenStack component which provides virtual networking services. Network types and some terms Before getting into the actual Neutron architecture, let us try to understand how Neutron provides virtual networking capabilities to compute instances. First, it … Continue reading OpenStack Neutron – architecture and overview

Understanding TLS certificates with NGINX and Ansible – part I

If you read technical posts like this one, chances are that you have already had some exposure to TLS certificates, for instance because you have deployed a service that uses TLS and needed to create and deploy certificates for the servers and potentially for clients. Dealing with certificates can be a challenge, and a sound … Continue reading Understanding TLS certificates with NGINX and Ansible – part I