Virtual WAN static routes redistribution

Azure Virtual WAN is one of the networking options offered by Azure, and routing inside of Virtual WAN has become a sort of dark art with the many supported options. Some years ago Routing Intent (also known as Routing Policies) was introduced to simplify routing, but at times you need to go back to the … Continue reading Virtual WAN static routes redistribution

Going beyond 8 peers in Azure Route Server

After a good while without posting anything, I finally decided to slowly recommence again. This first post is about a little BGP trick that may help you increase the scale of Azure Route Server. Typically the maximum number of 8 BGP peers should be enough for most designs, but if you happen to need to … Continue reading Going beyond 8 peers in Azure Route Server

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

ExpressRoute multi-region: triangles or squares?

The square design in ExpressRoute is not a recommended practice, but it can mean savings in ExpressRoute costs of up to 90%.

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

Designing your SDWAN and Firewall into Azure Hub and Spoke

Designing network connectivity in public cloud can very quickly become a daunting task. Of course, public cloud providers do offer native networking services, and with those it is fairly easy. This should always be your primary route (pun intended). For example, in the case of Azure, using Virtual WAN and its native integration with both … Continue reading Designing your SDWAN and Firewall into Azure Hub and Spoke

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

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)

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