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 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

Yet Another Demo App

I often need to learn how certain platforms work, and to achieve that there is no better way than deploying a sample workload and run some tests with it: for example for the “A day in the life of a packet on AKS” series that I wrote some years ago when AKS was something new … Continue reading Yet Another Demo App

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

Azure Bastion routing in Virtual WAN

As you might know, Azure Bastion enables management connectivity to virtual machines without having to assign them public IP addresses, and without having to maintain jump hosts in your Virtual Network. Up to recently, the virtual machines needed to be immediately peered to the VNet where Azure Bastion was deployed, but with IP-based connections Azure … Continue reading Azure Bastion routing in Virtual WAN

Importing Palo Alto policies to Azure Firewall

I recently had a project where we had the chance to convert a Palo Alto ruleset to an Azure Firewall Policy. I had recently created a script to generate a Firewall Policy for Microsoft 365 endpoints, so the challenge was using that work as a basis to generate an Azure Firewall Policy out of the … Continue reading Importing Palo Alto policies to Azure Firewall

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

Azure Firewall’s sidekick to join the BGP superheroes

Azure Firewall is a fantastic product: oversimplifying, an architecture that scales out great, provides traffic forwarding and security in Azure, and is very easy to integrate in a network. Some times you need to manipulate the default routing of Azure VNets, and Azure Route Server offers an invaluable tool for that. However, Azure Route Server … Continue reading Azure Firewall’s sidekick to join the BGP superheroes

AAD Application Proxy: Where is my WAF?

You might have read my previous intro post to the AAD Application Proxy, where I went over a quick intro to this service and a comparison with other reverse proxies available in the Azure portfolio. I finished that post with a very generic diagram describing how to combine multiple proxies to get different capabilities, for … Continue reading AAD Application Proxy: Where is my WAF?