Private Link reality bites – Private endpoints are an illusion

Welcome to this new series of blog posts in which I will be explaining some not-so-well-known facts about Azure Private Link and some associated technologies! This idea is born from the fact that I have been helping some colleagues and customers lately with some questions around Private Link, and that has made me realize that … Continue reading Private Link reality bites – Private endpoints are an illusion

Interregional traffic in hub-and-spoke

In Azure you have two main ways of managing your virtual network connectivity: self-managed hub-and-spoke and Virtual WAN. Virtual WAN is a solution where Microsoft manages part of your virtual networks for you, and in exchange it gives you some benefits such as any-to-any routing out of the box. However, what if you need that … Continue reading Interregional traffic in hub-and-spoke

Simulating VPN sites in Azure with Ubuntu 24.04 and StrongSwan

Disclaimer: this post is going to be quite geeky. So this is not the kind of post you want to read if you don’t need this stuff. But hey, I needed to tell someone after getting this to work, plus this might be useful for somebody else, since I struggled to find these details out … Continue reading Simulating VPN sites in Azure with Ubuntu 24.04 and StrongSwan

Do not let ExpressRoute, VPN and SDWAN traffic bypass your firewall

I have recently expanded my SDWAN in hub-and-spoke networks design guide to include SDWAN-to-firewall routing. Initially I didn’t have this point, but recent conversations have made me realize that not everybody understand this. The main difficulty in this topic is related to the fact that you cannot inspect the effective routes of your Virtual Network … Continue reading Do not let ExpressRoute, VPN and SDWAN traffic bypass your firewall

Monitoring Azure Networks with Alerts

Monitoring is one of those underrated disciplines: everybody tells you to do it, but nobody tells you exactly how. As a consequence, there are many different approaches and few concrete recommendations. Before continuing, a word of caution: I am not going to cover introductory topics in this post. If you are not familiar with Virtual … Continue reading Monitoring Azure Networks with Alerts

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

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

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)

Azure DNS Private Resolver without VNet Peerings

As you might already know, Azure DNS Private Resolver is an Azure service that support DNS forwarding between Azure and on-premises DNS servers. It is very useful to provide Azure DNS resolution to on-premises clients (for example to access private endpoints), or to provide on-premises DNS resolution to Azure clients (to access on-prem resources). Last … Continue reading Azure DNS Private Resolver without VNet Peerings

Azure Virtual WAN Hub Routing Preference

You probably know Azure Virtual WAN: it is an Azure service that provides any-to-any connectivity across regions out of the box, or a “global transit network architecture”, as they describe here: Essentially Virtual WAN is a set of Microsoft-managed virtual hubs peered to each other, where you would connect your VNets and/or branches (ExpressRoute, Site-to-Site … Continue reading Azure Virtual WAN Hub Routing Preference