About virtual network gateways for ExpressRoute
A virtual network gateway is used to send network traffic between Azure virtual networks and on-premises locations. You can use a virtual network gateway for either ExpressRoute traffic, or VPN traffic. This article focuses on ExpressRoute virtual network gateways.
When you create a virtual network gateway, you need to specify several settings. One of the required settings, '-GatewayType', specifies whether the gateway is used for ExpressRoute, or VPN traffic. The two gateway types are:
Vpn - To send encrypted traffic across the public Internet, you use the gateway type 'Vpn'. This is also referred to as a VPN gateway. Site-to-Site, Point-to-Site, and VNet-to-VNet connections all use a VPN gateway.
ExpressRoute - To send network traffic on a private connection, you use the gateway type 'ExpressRoute'. This is also referred to as an ExpressRoute gateway and is the type of gateway used when configuring ExpressRoute.
Each virtual network can have only one virtual network gateway per gateway type. For example, you can have one virtual network gateway that uses -GatewayType Vpn, and one that uses -GatewayType ExpressRoute.
When you create a virtual network gateway, you need to specify the gateway SKU that you want to use. When you select a higher gateway SKU, more CPUs and network bandwidth are allocated to the gateway, and as a result, the gateway can support higher network throughput to the virtual network.
ExpressRoute virtual network gateways can use the following SKUs:
If you want to upgrade your gateway to a more powerful gateway SKU, in most cases you can use the 'Resize-AzureRmVirtualNetworkGateway' PowerShell cmdlet. This will work for upgrades to Standard and HighPerformance SKUs. However, to upgrade to the UltraPerformance SKU, you will need to recreate the gateway. Recreating a gateway incurs downtime.
Estimated performances by gateway SKU
The following table shows the gateway types and the estimated performances. This table applies to both the Resource Manager and classic deployment models.
|Megabits per second||Packets per second||Connections per second||VPN Gateway and ExpressRoute coexist|
|Basic SKU (deprecated)||500||Unknown||Unknown||No|
|High Performance SKU||2,000||250,000||14,000||Yes|
|Ultra Performance SKU||10,000||1,000,000||28,000||Yes|
Application performance depends on multiple factors, such as the end-to-end latency, and the number of traffic flows the application opens. The numbers in the table represent the upper limit that the application can theoretically achieve in an ideal environment.
Zone-redundant gateway SKUs
You can also deploy ExpressRoute gateways in Azure Availability Zones. This physically and logically separates them into different Availability Zones, protecting your on-premises network connectivity to Azure from zone-level failures.
Zone-redundant gateways use specific new gateway SKUs for ExpressRoute gateway.
The new gateway SKUs also support other deployment options to best match your needs. When creating a virtual network gateway using the new gateway SKUs, you also have the option to deploy the gateway in a specific zone. This is referred to as a zonal gateway. When you deploy a zonal gateway, all the instances of the gateway are deployed in the same Availability Zone.
REST APIs and PowerShell cmdlets
For additional technical resources and specific syntax requirements when using REST APIs and PowerShell cmdlets for virtual network gateway configurations, see the following pages:
|REST API||REST API|
See ExpressRoute Overview for more information about available connection configurations.
See Create a virtual network gateway for ExpressRoute for more information about creating ExpressRoute gateways.
See Create a zone-redundant virtual network gateway for more information about configuring zone-redundant gateways.