What is the Azure ExpressRoute service?

As part of your project for the financial organization, you need to answer the following questions:

• What is Azure ExpressRoute?
• How does ExpressRoute integrate with on-premises and Azure networks?
• What benefits does ExpressRoute provide compared to other site-to-site connectivity options?
• Can ExpressRoute provide the finance company with the best possible network performance?

ExpressRoute overview

Azure ExpressRoute lets you seamlessly extend your on-premises networks into the Microsoft cloud. This connection between your organization and Azure is dedicated and private. Establishing an ExpressRoute connection enables you to connect to Microsoft cloud services like Azure, Office 365, and Dynamics 365. Security is enhanced, connections are more reliable, latency is minimal, and throughput is greatly increased.

Features and benefits of ExpressRoute

There are several benefits to using ExpressRoute as the connection service between Azure and on-premises networks.

Layer 3 connectivity

ExpressRoute provides Layer 3 (address-level) connectivity between your on-premises network and the Microsoft cloud through connectivity partners. These connections can be from a point-to-point, any-to-any network, or they can be virtual cross-connections through an exchange.

Built-in redundancy

Each connectivity provider uses redundant devices to ensure that connections established with Microsoft are highly available. You can configure multiple circuits to complement this feature. All redundant connections are configured with Layer 3 connectivity to meet SLAs.

Connectivity to Microsoft cloud services

ExpressRoute enables direct access to the following services in all regions:

• Microsoft Office 365
• Microsoft Dynamics 365
• Azure compute services, such as Azure Virtual Machines
• Azure cloud services, such as Azure Cosmos DB and Azure Storage

Office 365 is created so that it can be accessed securely and reliably via the internet. Because of this design, we recommend ExpressRoute for specific scenarios. The "Learn more" section at the end of this module includes a link about using ExpressRoute to access Office 365.

Across on-premises connectivity with ExpressRoute Global Reach

You can enable ExpressRoute Global Reach to exchange data across your on-premises sites by connecting your ExpressRoute circuits. For example, assume that you have a private datacenter in California connected to ExpressRoute in Silicon Valley. You have another private datacenter in Texas connected to ExpressRoute in Dallas. With ExpressRoute Global Reach, you can connect your private datacenters through two ExpressRoute circuits. Your cross-datacenter traffic travels through the Microsoft network.

Dynamic routing

ExpressRoute uses the Border Gateway Protocol (BGP) routing protocol. 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.

ExpressRoute connectivity models

ExpressRoute supports three models that you can use to connect your on-premises network to the Microsoft cloud:

• CloudExchange colocation
• Point-to-point Ethernet connection
• Any-to-any connection

Colocation at a cloud exchange

Colocated providers can normally offer both Layer 2 and Layer 3 connections between your infrastructure, which might be located in the colocation facility and the Microsoft cloud. For example, if your datacenter is colocated at a cloud exchange such as an internet service provider (ISP), you can request a virtual cross-connection to the Microsoft cloud.

Point-to-point Ethernet connection

Point-to-point connections provide Layer 2 and Layer 3 connectivity between your on-premises site and Microsoft Azure. You can connect your offices or datacenters to Azure by using the point-to-point links. For example, if you have an on-premises datacenter, you can use a point-to-point Ethernet link to connect to Microsoft.

Any-to-any networks

With any-to-any connectivity, you can integrate your wide area network (WAN) with Microsoft Azure by providing connections to your offices and datacenters. Azure integrates with your WAN connection to provide a seamless connection, just like you'd have between your datacenter and any branch offices.

With any-to-any connections, all WAN providers offer Layer 3 connectivity. For example, if you already use Multiprotocol Label Switching (MPLS) to connect to your branch offices or other sites in your organization, an ExpressRoute connection to Microsoft behaves just like another ___location on your private WAN.

Security considerations

With ExpressRoute, your data doesn’t travel over the public internet, so it's not exposed to the potential risks associated with internet communications. ExpressRoute is a private connection from your on-premises infrastructure to your Azure infrastructure. However, even if you have an ExpressRoute connection, certain requests are still sent over the public internet. Including, DNS queries, certificate revocation list checking, and Azure Content Delivery Network requests.