Virtual Network Gateways
Note: Virtual network gateways are a crucial component for connecting your virtual networks to on-premises networks or to other virtual networks.
What is a Virtual Network Gateway?
A virtual network gateway is a logical network resource that is used to send encrypted traffic between your Azure virtual network and your on-premises network through the public internet. It is also used to send traffic between your virtual networks in Azure.
There are two types of virtual network gateways:
- VPN gateways: Used for hybrid cloud scenarios. They enable you to connect your Azure VNet to your on-premises network or another Azure VNet.
- ExpressRoute gateways: Used for private connections between your on-premises network and Azure. This offers higher bandwidth, lower latency, and increased security compared to VPN.
VPN Gateways
VPN gateways provide a secure and encrypted tunnel over the public internet. They are suitable for various connectivity needs, including:
- Connecting to resources in an Azure virtual network from an on-premises network.
- Connecting two or more Azure virtual networks together (VNet-to-VNet connectivity).
- Connecting to Azure from a remote office or individual computers.
Configuring a VPN Gateway
To configure a VPN gateway, you typically need to:
- Create a virtual network gateway resource in Azure.
- Create a local network gateway to represent your on-premises network.
- Create a connection resource to link the virtual network gateway and the local network gateway.
Example Azure CLI command to create a VPN gateway:
az network vnet-gateway create --name MyVPNGateway --resource-group MyResourceGroup --location eastus --public-ip-address MyPublicIP --gateway-type Vpn --vpn-type RouteBased --sku VpnGw1 --vnet MyVNet
ExpressRoute Gateways
ExpressRoute gateways facilitate a private, dedicated connection to Azure. This offers several advantages:
- Higher Bandwidth: Supports higher speeds than VPN connections.
- Lower Latency: Provides more predictable and lower latency.
- Increased Reliability: Offers greater uptime and performance.
- Isolation: Traffic does not traverse the public internet.
An ExpressRoute gateway is created within your Azure virtual network and then linked to an ExpressRoute circuit provisioned with a connectivity provider.
Key Considerations
- Gateway SKU: Different SKUs offer varying levels of performance, throughput, and number of connections. Choose one that meets your requirements.
- Gateway Type: Select between VPN or ExpressRoute based on your connectivity needs and budget.
- Redundancy: Consider deploying active-active gateways for high availability.
- BGP: Border Gateway Protocol is essential for dynamic routing between your on-premises network and Azure.
Understanding and properly configuring virtual network gateways is fundamental to establishing secure and efficient hybrid and multi-cloud architectures on Azure.
Important: Always consult the latest Azure documentation for specific configuration steps and pricing details, as these can change over time.