To associate an NSG with a subnet, execute the following command:
$vnet = Get-AzureRmVirtualNetwork -Name 'Packt-Script' -ResourceGroupName 'Packt-Networking-Script'$subnet = Get-AzureRmVirtualNetworkSubnetConfig -VirtualNetwork $vnet -Name BackEnd$nsg = Get-AzureRmNetworkSecurityGroup -ResourceGroupName 'Packt-Networking-Script' -Name 'nsg1'$subnet.NetworkSecurityGroup = $nsgSet-AzureRmVirtualNetwork -VirtualNetwork $vnet