Update create-custom-ip-address-prefix-powershell.md

fixed the module 
-------
cc: @asudbring

Author: brianlehr

articles/virtual-network/ip-services/create-custom-ip-address-prefix-powershell.md

@@ -26,7 +26,7 @@ The steps in this article detail the process to:
 - An Azure account with an active subscription. [Create an account for free](https://azure.microsoft.com/free/?WT.mc_id=A261C142F).
 - Azure PowerShell installed locally or Azure Cloud Shell.
 - Sign in to Azure PowerShell and ensure you've selected the subscription with which you want to use this feature.  For more information, see [Sign in with Azure PowerShell](/powershell/azure/authenticate-azureps).
-- Ensure your Az.Network module is 4.3.0 or later. To verify the installed module, use the command Get-InstalledModule -Name "Az.Network". If the module requires an update, use the command Update-Module -Name "Az.Network" if necessary.
+- Ensure your Az.Network module is 5.1.1 or later. To verify the installed module, use the command Get-InstalledModule -Name "Az.Network". If the module requires an update, use the command Update-Module -Name "Az.Network" if necessary.
 - A customer owned IPv4 range to provision in Azure.
     - A sample customer range (1.2.3.0/24) is used for this example. This range won't be validated by Azure. Replace the example range with yours.
 
@@ -200,4 +200,4 @@ As before, the operation is asynchronous. Use [Get-AzCustomIpPrefix](/powershell
 
 - To create a custom IP address prefix using the Azure CLI, see [Create custom IP address prefix using the Azure CLI](create-custom-ip-address-prefix-cli.md).
 
-- To create a custom IP address prefix using the Azure portal, see [Create a custom IP address prefix using the Azure portal](create-custom-ip-address-prefix-portal.md).
+- To create a custom IP address prefix using the Azure portal, see [Create a custom IP address prefix using the Azure portal](create-custom-ip-address-prefix-portal.md).