Azure VNet Peering and fewer VM reboots

This morning I woke up to a nice email from Microsoft Azure. The occasional “pricing and services updates”. From time to time, some really awesome features shows up in these mails, and this one had more than one!

VNet Peering

This one has been on the drawing board for quite a while. I remember talking to the networking team about it a long time. It will allow you to connect virtual networks, and not dealing with VPN Gateways. Of course, if you want to connect to networks outside of Azure, you will still need to use VPN or ExpressRoute. So what can we do with this peering? You can:

  • Route traffic between virtual networks, using the Azure backbone
  • Cross-subscription peering is supported
  • Cross ASM-ARM peering is also supported – ASM to ASM is not!
  • Route traffic through a VPN gateway in a different network, to access on premises resources

The documentation is lacking for the feature right now. Looking at Azure PowerShell changelog on GitHub, a few new commands was added in v1.6.0 which was released recently. The commands are:

  • Add-AzureRmVirtualNetworkPeering
  • Get-AzureRmVirtualNetworkPeering
  • Remove-AzureRmVirtualNetworkPeering
  • Set-AzureRmVirtualNetworkPeering

You have to register for the feature to use it at the moment though. Do this through PowerShell:

Register-AzureRmProviderFeature -ProviderNameSpace Microsoft.Network -FeatureName AllowVnetPeering

More info very soon!

In-place VM Migration

From time to time Microsoft updates the underlying hosts we’re using for our VMs. This has previously required reboot of the VMs since the host would also reboot during this maintenance. Now a new feature has been added, and thus reboots are not required for some updates anymore.

Your VM will however be paused for up to 30 seconds, but your temp disk and memory state is saved. If you haven’t noticed, this is already being used, and over time more and more hosts OS updates will support it. The goal is of course to never be require reboots.

This does not mean you will get single instance SLA though! Check this post for more info:


  1. I have desperately been waiting for this feature and jumped for joy when I saw the subtle announcement, but information on this topic is almost non-existent. Your post looks promising, but I don’t want to setup PowerShell. Do you know of a way to do this through the Azure Web Interface? Or CLI?


    1. The network team is working on documentation. From what I know it’s PowerShell and API (templates) from the beginning. Portal will be added later on. Let me know if you need more details. I’ll do another post when I have the details to configure it. Probably Monday or Tuesday ?


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