ExpressRoute prerequisites & checklist
To connect to Microsoft cloud services using ExpressRoute, you need to verify that the following requirements listed in the following sections have been met.
Microsoft 365 was created to be accessed securely and reliably via the Internet. Because of this, we recommend ExpressRoute for specific scenarios. For information about using ExpressRoute to access Microsoft 365, visit Azure ExpressRoute for Microsoft 365.
- A valid and active Microsoft Azure account. This account is required to set up the ExpressRoute circuit. ExpressRoute circuits are resources within Azure subscriptions. An Azure subscription is a requirement even if connectivity is limited to non-Azure Microsoft cloud services, such as Microsoft 365.
- An active Microsoft 365 subscription (if using Microsoft 365 services). For more information, see the Microsoft 365 specific requirements section of this article.
- You can work with an ExpressRoute connectivity partner to connect to the Microsoft cloud. You can set up a connection between your on-premises network and Microsoft in three ways.
- If your provider is not an ExpressRoute connectivity partner, you can still connect to the Microsoft cloud through a cloud exchange provider.
- Redundancy at each peering location: Microsoft requires redundant BGP sessions to be set up between Microsoft’s routers and the peering routers on each ExpressRoute circuit (even when you have just one physical connection to a cloud exchange).
- Redundancy for Disaster Recovery: Microsoft strongly recommends you set up at least two ExpressRoute circuits in different peering locations to avoid a single point of failure.
- Routing: depending on how you connect to the Microsoft Cloud, you or your provider needs to set up and manage the BGP sessions for routing domains. Some Ethernet connectivity providers or cloud exchange providers may offer BGP management as a value-add service.
- NAT: Microsoft only accepts public IP addresses through Microsoft peering. If you are using private IP addresses in your on-premises network, you or your provider needs to translate the private IP addresses to the public IP addresses using the NAT.
- QoS: Skype for Business has various services (for example; voice, video, text) that require differentiated QoS treatment. You and your provider should follow the QoS requirements.
- Network Security: consider network security when connecting to the Microsoft Cloud via ExpressRoute.
If you plan to enable Microsoft 365 on ExpressRoute, review the following documents for more information about Microsoft 365 requirements.
- Azure ExpressRoute for Microsoft 365
- Routing with ExpressRoute for Microsoft 365
- High availability and failover with ExpressRoute
- Microsoft 365 URLs and IP address ranges
- Network planning and performance tuning for Microsoft 365
- Network and migration planning for Microsoft 365
- Microsoft 365 integration with on-premises environments
- ExpressRoute on Office 365 advanced training videos
- For more information about ExpressRoute, see the ExpressRoute FAQ.
- Find an ExpressRoute connectivity provider. See ExpressRoute partners and peering locations.
- Refer to requirements for Routing, NAT, and QoS.
- Configure your ExpressRoute connection.