Azure ExpressRoute Overview

Azure ExpressRoute lets you create private connections between Azure datacenters and your on-premises infrastructure or colocation environment. ExpressRoute connections do not go over the public Internet. This offers higher reliability, faster speeds, lower latencies, and greater security than typical Internet connections.

What is ExpressRoute?

ExpressRoute provides a dedicated, private network connection from your on-premises network to Microsoft's network. This connection can be established through a connectivity provider, at a colocation facility, or directly from your network to a Microsoft peering location.

Key Benefits

• Higher Reliability: ExpressRoute connections are designed for high availability and can be configured with redundant paths for fault tolerance.
• Faster Speeds: You can provision ExpressRoute circuits with bandwidths from 50 Mbps to 10 Gbps, providing predictable performance.
• Lower Latency: By connecting directly to Microsoft's network, ExpressRoute bypasses the public Internet, reducing latency for your applications.
• Enhanced Security: Traffic stays within the private network, reducing exposure to public Internet threats.
• Predictable Performance: Unlike the Internet, ExpressRoute offers guaranteed bandwidth and traffic shaping.
• Global Reach: Connect to Azure regions worldwide through a network of connectivity partners and peering locations.

How ExpressRoute Works

ExpressRoute uses a combination of connectivity providers and peering locations. You choose a connectivity provider and a peering location that is convenient for your on-premises network. The provider establishes a Layer 2 or Layer 3 connection from your network to the ExpressRoute edge router at the peering location. From there, the connection extends to Microsoft's global network.

Connectivity Options

ExpressRoute offers several connectivity options:

• Cloud Exchange Co-location: Connect to Azure through a cloud exchange provider at a colocation facility. This is a popular choice for flexibility and access to multiple cloud providers.
• Point-to-Point Ethernet Circuit: Establish a direct, dedicated Layer 2 connection from your premises to an ExpressRoute peering location.
• Any-to-Any (IP VPN) Network: Leverage an existing IP VPN network from a supported service provider to connect to Azure.

Peering in ExpressRoute

ExpressRoute supports three types of peering, allowing you to connect to different Microsoft services:

• Azure Private Peering: Connect to your Azure Virtual Networks (VNets).
• Azure Public Peering: Connect to Azure public services (e.g., Azure Storage, Azure SQL Database) via their public IP addresses.
• Microsoft Peering: Connect to Microsoft 365 services (e.g., Office 365) and Dynamics 365.

Use Cases

ExpressRoute is ideal for:

• Migrating large datasets to Azure.
• Disaster recovery and business continuity solutions.
• Connecting hybrid cloud environments.
• Running line-of-business applications that require high bandwidth and low latency.
• Ensuring predictable performance for critical workloads.

To get started with ExpressRoute, you'll need to work with a supported ExpressRoute connectivity partner.

# This is a conceptual representation, actual configuration involves CLI/Portal/API
resource "azurerm_express_route_circuit" "example" {
  name                = "myExpressRouteCircuit"
  resource_group_name = azurerm_resource_group.example.name
  location            = azurerm_resource_group.example.location
  sku {
    tier   = "Standard"
    family = "Metered"
  }
  service_provider_properties {
    peering_location = "Equinix NY"
    bandwidth_in_mbps = 1000
  }
}