Azure ExpressRoute

• Azure ExpressRoute lets you extend your on-premises networks into the Microsoft cloud over a private connection, with the help of a connectivity provider.
• You can establish connections to Microsoft cloud services, such as Microsoft Azure and Microsoft 365.
• Allows you to connect offices, datacenters, or other facilities to the Microsoft cloud
• Each location would have its own ExpressRoute circuit.
• Connectivity can be from an any-to-any (IP VPN) network, a point-to-point Ethernet network, or a virtual cross-connection through a connectivity provider at a colocation facility.
• ExpressRoute connections don't go over the public Internet. This allows ExpressRoute connections to offer more reliability, faster speeds, consistent latencies, and higher security than typical connections over the Internet.

Features and benefits of ExpressRoute

Connectivity to Microsoft cloud services

• Connectivity to Microsoft cloud services such as Office 365, Dynamics 365, Azure Services.

Global connectivity

• You can enable ExpressRoute Global Reach to exchange data across your on-premises sites by connecting your ExpressRoute circuits to the Microsoft network.
• For example, say you had an office in Asia and a datacenter in Europe, both with ExpressRoute circuits connecting them to the Microsoft network.

Dynamic routing

• ExpressRoute uses the BGP.
• BGP is used to exchange routes between on-premises networks and resources running in Azure.
• This protocol enables dynamic routing between your on-premises network and services running in the Microsoft cloud.

Built-in redundancy

• Each connectivity provider uses redundant devices to ensure that connections are highly available.

Connectivity models

Co-location at a cloud exchange

• Co-location refers to your facility being physically co-located at a cloud exchange, such as an ISP.
• You can request a virtual cross-connect to the Microsoft cloud.

Point-to-point Ethernet connection

• Use a point-to-point connection to connect your facility to the Microsoft cloud.

Any-to-any networks

• With any-to-any connectivity, you can integrate your wide area network (WAN) with Azure

Directly from ExpressRoute sites

• You can connect directly into the Microsoft's global network at a peering location strategically distributed across the world.
• ExpressRoute Direct provides dual 100 Gbps or 10-Gbps connectivity, which supports Active/Active connectivity at scale.

Security considerations

• Your data doesn't travel over the public internet, so it's not exposed to the potential risks associated with internet communications
• DNS queries, certificate revocation list checking, and Azure Content Delivery Network requests are still sent over the public internet.