IPvlan with Docker in Azure

Today I was looking at IPvlan on a docker container in Azure along a colleague, and we found that there are plenty of documentation and blogs out there that might be confusing when running this setup on Azure. What is this IPvlan thing, I hear you ask? Docker has a good explanation here, but let … Continue reading IPvlan with Docker in Azure

You want to use AS-path as your virtual hub routing preference

Wow, that was a long title. Let me give you another one: if you haven’t tested your High Availability (HA) or Disaster Recovery (DR) plans, you shouldn’t rely on them. This is of course regardless of whether your infrastructure runs on your premises, on public cloud, or anywhere else. In this post I am going … Continue reading You want to use AS-path as your virtual hub routing preference

Getting visibility into your Azure Traffic with NSG Flow Logs

In every network you want to know what traffic is using it. Networking devices offer multiple options to report on traffic, such as Netflow, sFlow or IPFIX. However, these options are often not available in public clouds. For example, in Azure the next closest thing are NSG Flow Logs, which you can enable in your … Continue reading Getting visibility into your Azure Traffic with NSG Flow Logs

Virtual Network Gateways routing in Azure

If you have ever used Azure, you probably have used one of these Virtual Network Gateways too: whether it is to connect your branches and headquarters with Azure via IPsec VPN or ExpressRoute, or to provide connectivity to your mobile workers or external partners through Point-to-Site VPNs. In this post I will go deep on … Continue reading Virtual Network Gateways routing in Azure

Azure Networking is not like your on-onprem network

I often get asked about the differences between Azure Networking and a traditional, on-premises network. I have been hit with a flu the last few days, so I had some time to think about this, and I decided to start writing whatever thoughts were not actually the result of the fever. In this post I … Continue reading Azure Networking is not like your on-onprem network

Filtering AKS egress traffic with Virtual WAN

If you are reading my blog you probably know what Virtual WAN and Azure Kubernetes Service are. You probably know as well that you can configure AKS so that egress traffic is sent through an Azure Firewall by using Azure routing as described in the article Control Egress Traffic in AKS. That article explains how … Continue reading Filtering AKS egress traffic with Virtual WAN

VRFs and Virtual WAN

Some organizations use Virtual Routing and Forwarding (VRF) tables in their networks to segment traffic at the routing level. Transporting that concept to Azure can be challenging, since virtualizing an Azure network is not easy. If you think about it, your Azure network is already its own VRF in a way, it is a slice … Continue reading VRFs and Virtual WAN

Azure Hub And Spoke 2.0

I have recently had a couple of recent conversations that have made me reconsider the way we traditionally implement the hub and spoke Virtual Network design in Azure, which has some limitations. The idea is to introduce a relatively simple but powerful modification to the design that achieves these objectives: TL,DR: The main modification introduced … Continue reading Azure Hub And Spoke 2.0

Overlapping IP addresses in a hub-and-spoke network (feat. AVNM & ARS)

I have had some questions around a common theme asked by some large Azure customers. These refrains might sound familiar to you: “I have run out of IPv4 addresses“, “My network team can only allocate so many IPs for Azure“, “How can I reuse IP space in Azure?“. If they do, I have a hack … Continue reading Overlapping IP addresses in a hub-and-spoke network (feat. AVNM & ARS)

Combining Azure Firewall and Flow Log analysis

As you might already know, there are a couple of ways of filtering traffic in Azure Virtual Networks: Network Security Groups (NSGs) and Azure Firewall. NSGs offer unlimited performance for Layer 4 filtering, while Azure Firewall is more powerful with features like deep packet inspection or application-level intelligence. However, even if these solutions follow a … Continue reading Combining Azure Firewall and Flow Log analysis