Merge pull request #48667 from anavinahar/VNetPeeringFAQ

VNet peering FAQ

Author: PRMerger19

articles/virtual-network/virtual-networks-faq.md

@@ -13,7 +13,7 @@ ms.devlang: na
 ms.topic: article
 ms.tgt_pltfrm: na
 ms.workload: infrastructure-services
-ms.date: 03/01/2018
+ms.date: 08/09/2018
 ms.author: jdial
 
 ---
@@ -40,7 +40,6 @@ Visit the [Virtual network documentation](https://docs.microsoft.com/azure/virtu
 Yes. You can use a VNet without connecting it to your premises. For example, you could run Microsoft Windows Server Active Directory domain controllers and SharePoint farms solely in an Azure VNet.
 
 ### Can I perform WAN optimization between VNets or a VNet and my on-premises data center?
-
 Yes. You can deploy a [WAN optimization network virtual appliance](https://azure.microsoft.com/marketplace/?term=wan+optimization) from several vendors through the Azure Marketplace.
 
 ## Configuration
@@ -187,7 +186,6 @@ Yes. You can (optionally) deploy Cloud Services role instances within VNets. To
 Yes. You must connect a VMSS to a VNet.
 
 ### Is there a complete list of Azure services that can I deploy resources from into a VNet?
-
 Yes, For details, see [Virtual network integration for Azure services](virtual-network-for-azure-services.md).
 
 ### Which Azure PaaS resources can I restrict access to from a VNet?
@@ -221,3 +219,36 @@ Yes. Learn more about using:
 - The Azure portal to deploy VNets through the [Azure Resource Manager](manage-virtual-network.md#create-a-virtual-network) and [classic](virtual-networks-create-vnet-classic-pportal.md) deployment models.
 - PowerShell to manage VNets deployed through the [Resource Manager](/powershell/module/azurerm.network) and [classic](/powershell/module/azure/?view=azuresmps-3.7.0) deployment models.
 - The Azure command-line interface (CLI) to deploy and manage VNets deployed through the [Resource Manager](/cli/azure/network/vnet) and [classic](../virtual-machines/azure-cli-arm-commands.md?toc=%2fazure%2fvirtual-network%2ftoc.json#azure-network-commands-to-manage-network-resources) deployment models.  
+
+## VNet peering
+
+### Can I create a peering connection to a VNet in a different region?
+Yes. Global VNet peering enables you to peer VNets in different regions. Global VNet peering is available in all Azure public regions. You cannot globally peer from Azure public regions to National clouds. Global peering is not currently available in national clouds.
+
+### Can I enable VNet Peering if my virtual networks belong to subscriptions within different Azure Active Directory tenants?
+Currently it is not possible to establish VNet Peering (whether local or global) if your subscriptions belong to different Azure Active Directory tenants.
+
+### My VNet peering connection is in *Initiated* state, why can't I connect?
+If your peering connection is in an Initiated state, this means you have created only one link. A bidirectional link must be created in order to establish a successfuly connection. For example, to peer VNet A to VNet B, a link must be created from VNetA to VNetB and from VNetB to VNetA. Creating both links will change the state to *Connected.*
+
+### Can I peer my VNet with a VNet in a different subscription?
+Yes. You can peer VNets across subscriptions and across regions.
+
+### Can I peer two VNets with matching or overlapping address ranges?
+No. Address spaces must not overalap to enable VNet Peering.
+
+### How much do VNet peering links cost?
+There is no charge for creating a VNet peering connection. Data transfer across peering connections is charged. [See here](https://azure.microsoft.com/pricing/details/virtual-network/).
+
+### Is VNet peering traffic encrypted?
+No. Traffic between resources in peered VNets is private and isolated. It remains completely on the Microsoft Backbone.
+
+### Why is my peering connection in a disconnected state?
+VNet peering connections go into *Disconnected* state when one VNet peering link is deleted. You must delete both links in order to reestablish a successful peering connection.
+
+### If I peer VNetA to VNetB and I peer VNetB to VNetC, does that mean VNetA and VNetC are peered?
+No. Transitive peering is not supported. You must peer VNetA and VNetC for this to take place.
+
+### Are there any bandwidth limitations for peering connections?
+No. VNet peering, whether local or global, does not impose any bandwidth restrictions. Bandwidth is only limites by the VM or compute resource.
+