Express Route Virtual Network Gateway

Virtual Network Gateway 

In Order to connect to Azure Virtual Network , and On-Premises Network via Express Route , Enterprise must create a Virtual Network gateway. 

A Virtual network gateway serves two purpose: 

• It Exchanges IP routes between networks 
• Route Network Traffic 

Gateway Types

Once Enterprise plan to create a Virtual Network gateway , We have to provide following setting:

Like Gateway Types (Express Route or  VPN traffic ).

VPN:  In order to send the encrypted traffic across a public Network , Enterprise should use the Gateway type :  Vpn, also called Vpn Gateway. For Site-to-Site , Point-to-Site and Vnet-toVnet connection , Enterprise should use VPN gateway. 

ExpressRoute: In Order to send the Network Traffic on Private Connection , Enterprise should use the gateway type : ‘ExpressRoute’. This type of gateway is used when configuring ExpressRoute. 

Each Virtual Network can have only one Virtual Network gateway per gateway type. Example : Enterprise can have one Virtual Network gateway that uses  -GatewayType Vpn and one that uses -GatewayType  ExpressRoute. 

Gateway SKUs

When Enterprise wants to create a Virtual network gateway , you need to define the SKu types.

Enterprises must select the Gateway SKu based on their requirement and amount of traffic . 

ExpressRoute Virtual Network gateway can use the following SKUs. 

• Standard
• HighPerformance 
• UltraPerformance 
• ErGw1Az
• ErGw2Az
• ErGw3Az

If an Enterprise wants to upgrade their gateway to a more Powerful gateway SKU, Enterprise should use the  Resize-AzVirtualNetworkGateway Powershell cmdlet or perform the upgrade directly in ExpressRoute Virtual network gateway Configuration blade in Azure Portal. 

Below are the following upgrades supported. 

• Standard to High Performance 
• Standard to Ultra Performance 
• High Performance to Ultra Performance 
• ErGw1AZ to ErGw2AZ
• ErGw1AZ to ErGw3AZ
• ErGw2AZ to ErGw3AZ
• Default to Standard. 

Also Enterprise can downgrade the Virtual network gateway SKU. Below downgrades are supported. 

• High Performance to Standard 
• ErGw2AZ to ErGw1AZ 

For all other downgrades scenarios , you will need to delete and recreate the gateway and this incurs downtime.