Crosspost from Pebkac.io – MikroTik CHR in Microsoft Azure (ARM)

This post originally from Pebkac.io and reproduced with permission.

At the time of writing, Mikrotik’s current CHR build is 6.35rc49.

While purported to work in a Hyper-V VM, there are no instructions I could find to get one up and running in Microsoft Azure (with ARM).

Knowing that it should be theoretically possible, given Azure utilises a hypervisor with the same origins as Hyper-V, I went down the rabbit hole.

The salient points are as follows:

• It works! We have stable CHRs in ARM VMs supporting production workloads.
• You must convert the Mikrotik supplied VHDX to a VHD before uploading to Azure’s blob storage, as Azure doesn’t support the newer format. (I installed the Hyper-V role on my Windows box, which includes a utility to do the conversion)
• You must use the -CreateOption Attach parameter with the Set-AzureRmVMOSDiskcmdlet, otherwise you’ll end up with an Azure VM object stuck in a “Provisioning” or “Creating” state. You can just use the URL for the VHD you upload to blob storage for the -VhdUri parameter.
• The CHR VM doesn’t respond to Stop or Restart requests from the Resource Manager Portal or PowerShell cmdlets. Attempting these actions can put the CHR VM into an inconsistent state.
• You can safely delete CHR VMs and the disks are left intact in blob storage and can be re-attached to a new VM. (Would need to re-license)
• You can restart the router from within Winbox / CLI as well as perform upgrades. (Back up your config first, sometimes the upgrades fail) Ed – This is a release client remember!
• A lot of scenarios will require IP forwarding to be enabled on your CHR NIC. This can only be done with PowerShell, set the EnableIPForwarding property to true on a NIC object and then update with Set-AzureRmNetworkInterface

If Mikrotik are not forthcoming with some proper Azure instructions, I’ll try and expand on these notes with a full set of step by step instructions.

NB: If you’re at the point where you’re still choosing your cloud provider, CHR is presently much more mature in Amazon (AWS) on EC2 instances.