Frequently Asked Question
Dynamic MAC - Niagara in a Virtual Machine
Last Updated 8 years ago
It is now commonplace to see virtual servers (or machines) replacing what once would have been racks upon racks of physical servers. This consolidation allows for much better utilisation of computing resource, and more importantly much less energy consumed. I come from an IT infrastructure background and have been involved in several large scale virtualisation projects.
This brings me onto a specific use case: Niagara AX running in a virtual environment.
I have first hand experience running Niagara AX within HyperV and VMWare ESXi environments and it works exactly like any other way of installing it on physical kit.There is however one main factor that can cause a problem, we have noticed it ourselves and on clients own virtual environments. So its worth a quick post about what this is exactly.
Dynamic MAC addressing is a feature that hypervisors use to give the VM’s network adapter a unique hardware address on the network, even though its not hardware. Dynamic MAC addressing allows for the (highly unlikely) possibility that the mac address of two VM’s end up being the same, the hypervisor has the ability to dynamically change the MAC’s of VM’s across a cluster to make sure this doesn’t happen.
This has a downside since Niagara AX licenses use the MAC address in their unique HOST ID calculation, therefore if the MAC address of a VM changes, the Niagara AX license will become invalid since the HOST ID has changed.
Fortunately the two most common hypervisors provide the option to statically set a VM’s MAC address and i would suggest this option is set every time a virtual instance of Niagara AX is built.
The moral of this story is: When running Niagara AX in a virtual machine, make sure its MAC address is statically set!
This brings me onto a specific use case: Niagara AX running in a virtual environment.
I have first hand experience running Niagara AX within HyperV and VMWare ESXi environments and it works exactly like any other way of installing it on physical kit.There is however one main factor that can cause a problem, we have noticed it ourselves and on clients own virtual environments. So its worth a quick post about what this is exactly.
Dynamic MAC addressing is a feature that hypervisors use to give the VM’s network adapter a unique hardware address on the network, even though its not hardware. Dynamic MAC addressing allows for the (highly unlikely) possibility that the mac address of two VM’s end up being the same, the hypervisor has the ability to dynamically change the MAC’s of VM’s across a cluster to make sure this doesn’t happen.
This has a downside since Niagara AX licenses use the MAC address in their unique HOST ID calculation, therefore if the MAC address of a VM changes, the Niagara AX license will become invalid since the HOST ID has changed.
Fortunately the two most common hypervisors provide the option to statically set a VM’s MAC address and i would suggest this option is set every time a virtual instance of Niagara AX is built.
The moral of this story is: When running Niagara AX in a virtual machine, make sure its MAC address is statically set!