Q. Can I use a Network Load Balancing feature in Azure?
Windows Server has a Network Load Balancing feature which, as the name suggests, enables the load balancing of traffic between servers running the Network Load Balancing feature. This feature uses layer-two broadcast or multicast to enable the distribution of incoming traffic to all nodes participating in the NLB cluster. Azure does not support layer-two broadcast/multicast, which means the NLB feature of Windows cannot be used in Azure. This is confirmed at https://support.microsoft.com/en-us/kb/2721672?wa=wsignin1.0.
Instead, you should leverage the load balancing features of Azure. These can be used for cloud service endpoints, or as a discrete load balancer in the new Azure Resource Manager model. Additionally, the Internal Load Balancer can be used to balance traffic between VMs within an Azure Virtual Network.