Thoughts from the clouds
Yesterday I got an interesting question. How does subnet peering interact with ExpressRoute? A quick look into the official docs for Subnet peering checks and limitations didn’t give any answers, and Copilot wasn’t very helpful either: So let’s dive in! What was subnet peering again? I wrote a blog post some time ago here, feel … Continue reading Subnet peering and ExpressRoute
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
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
The square design in ExpressRoute is not a recommended practice, but it can mean savings in ExpressRoute costs of up to 90%.
You might have heard about VNet Flow Logs, I posted about this new Azure feature here. One of the applications of VNet Flow Logs is to gain visibility into traffic in places that had been blind spots until now, such as in the Gateway Subnets to inspect traffic on VPN or ExpressRoute. Talking about ExpressRoute, … Continue reading ExpressRoute traffic visibility: Flow Logs or Traffic Collector?
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
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
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
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
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
Cloudtrooper 