Merge pull request #219302 from brianlehr/patch-36

Update custom-ip-address-prefix.md

Author: prmerger-automator[bot]

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

@@ -48,18 +48,21 @@ When ready, you can issue the command to have your range advertised from Azure a
 
 * A custom IP prefix must be associated with a single Azure region.
 
-* An IPv4 range can be equal or between /21 to /24.  An IPv6 range can be equal or between /46 to /48.
+* An IPv4 range can be equal or between /21 to /24.  An IPv6 range must be /48.
 
 * Custom IP prefixes do not currently support derivation of IPs with Internet Routing Preference or that use Global Tier (for cross-region load-balancing).
 
-* In regions with [availability zones](../../availability-zones/az-overview.md), a custom IPv4 prefix (or a regional custom IPv6 prefix) must be specified as either zone-redundant or assigned to a specific zone. It can't be created with no zone specified in these regions. All IPs from the prefix must have the same zonal properties.
+* In regions with [availability zones](../../availability-zones/az-overview.md), a custom IPv4 prefix (or a regional custom prefix) must be specified as either zone-redundant or assigned to a specific zone. It can't be created with no zone specified in these regions. All IPs from the prefix must have the same zonal properties.
 
 * The advertisements of IPs from a custom IP prefix over Azure ExpressRoute aren't currently supported.
 
 * Once provisioned, custom IP prefix ranges can't be moved to another subscription. Custom IP address prefix ranges can't be moved within resource groups in a single subscription. It is possible to derive a public IP prefix from a custom IP prefix in another subscription with the proper permissions as described [here](create-custom-ip-address-prefix-powershell.md).
 
 * IPs brought to Azure may have a delay up to 2 weeks before they can be used for Windows Server Activation.
 
+> [!IMPORTANT]
+> There are several differences between how custom IPv4 and IPv6 prefixes are onboarded and utilized.  Please see [Differences between using BYOIPv4 and BYOIPv6](create-custom-ip-address-prefix-ipv6-powershell.md#differences-between-using-byoipv4-and-byoipv6) for more details.
+
 ## Pricing
 
 * There is no charge to provision or use custom IP prefixes. There is no charge for any public IP prefixes and public IP addresses that are derived from custom IP prefixes.
@@ -68,8 +71,8 @@ When ready, you can issue the command to have your range advertised from Azure a
 
 ## Next steps
 
-- To create a custom IP address prefix using the Azure portal, see [Create custom IPv4 address prefix using the Azure portal](create-custom-ip-address-prefix-portal.md).
+- To create a custom IPv4 address prefix using the Azure portal, see [Create custom IPv4 address prefix using the Azure portal](create-custom-ip-address-prefix-portal.md).
 
-- To create a custom IP address prefix using PowerShell, see [Create a custom IPv4 address prefix using Azure PowerShell](create-custom-ip-address-prefix-powershell.md).
+- To create a custom IPv4 address prefix using PowerShell, see [Create a custom IPv4 address prefix using Azure PowerShell](create-custom-ip-address-prefix-powershell.md).
 
 - For more information about the management of a custom IP address prefix, see [Manage a custom IP address prefix](create-custom-ip-address-prefix-powershell.md).