Direct Connect Best Practices

Direct Connect establishes high-speed, low-latency, stable, and secure dedicated network connections that connect your on-premises data center to the cloud.

You can use Direct Connect together with other cloud services to set up networks flexibly. You can refer to the best practices provided here for typical networking solutions.

**Table 1** Scenarios
Solution	Example Scenario	Cloud Services	Description
Connecting an on-premises data center to VPCs in the same region	Using a single Direct Connect connection: Connecting an On-Premises Data Center to a VPC over a Single Connection and Using Static Routing to Route Traffic Connecting an On-Premises Data Center to a VPC over a Single Connection and Using BGP Routing to Route Traffic	Direct Connect VPC ECS	You can use a single connection with a virtual gateway associated to connect an-premises data center to a VPC and leverage the large bandwidth and private connectivity for fast, secure, stable data transmission
	Connecting an On-Premises Data Center to a VPC over Two Connections in Load Balancing Mode (Virtual Gateway)	Direct Connect VPC ECS	To improve the network performance and reliability, you can deploy two connections to connect an on-premises data center to the VPC. The two connections work in load balancing mode. When both connections work normally, the network transmission capability is greatly improved. If one connection becomes faulty, the other connection is not a single point of failure, and your on-premises data center can still access the VPCs.
	Connecting an On-Premises Data Center to a VPC over Two Connections in an Active/Standby Pair (Virtual Gateway)	Direct Connect VPC ECS	You want to ensure high reliability of the hybrid cloud network, while enjoying the following benefits: A more cost-effective connection can be used as the standby one to lower costs. The outbound connection is specified, which simplifies O&M. You can create two connections that work in an active/standby pair. If the active connection becomes faulty, the standby one will automatically take over, which minimizes service interruptions.
	Connecting an On-Premises Data Center to Multiple VPCs that Do Not Need to Communicate with Each Other	Direct Connect VPC ECS	You can create a single standard connection with multiple virtual gateways associated to access different VPCs. This enables end-to-end route isolation for different services.
	Connecting an On-Premises Data Center to Multiple VPCs in the Same Region Using Direct Connect and VPC Peering	Direct Connect VPC ECS	After you connect an on-premises data center to a VPC using Direct Connect, you can use VPC Peering to peer this VPC with other VPCs in the same region, so that the on-premises data center can access all connected VPCs.
Connecting an on-premises data center to a VPC in the same region using Direct Connect and Enterprise Router	Setting Up a Hybrid Cloud Network Using Enterprise Router and Direct Connect Global DC Gateway	Enterprise Router Direct Connect (global DC gateway) VPC ECS	Suppose your enterprise has deployed two VPCs in a region. The two VPCs need to communicate with each other and communicate with your on-premises data center through a global DC gateway.
	Setting Up a Hybrid Cloud Network Using Enterprise Router and a Pair of Direct Connect Connections (Global DC Gateway)	Enterprise Router Direct Connect (global DC gateway) VPC ECS	An enterprise router enables dynamic route selection and switchover between connections that work in load balancing mode. This expands the network bandwidth, increases the network throughput, improves network performance, and ensures high reliability. By attaching global DC gateways to enterprise routers, you can set up a large-scale hybrid cloud network that meets your communication requirements.
	Setting Up a Hybrid Cloud Network Using Enterprise Router and a Pair of Active/Standby Direct Connect Connections (Global DC Gateway)	Enterprise Router Direct Connect (global DC gateway) VPC ECS	To improve the reliability of the hybrid cloud network and reduce costs, you can create two connections that work in an active/standby pair and use an enterprise router for dynamic route selection and switchover between the connections. If the active connection becomes faulty, the standby one will automatically take over, which minimizes service interruptions.
Using a public NAT gateway and Direct Connect to accelerate Internet access	Using a Public NAT Gateway and Direct Connect to Accelerate Internet Access	Direct Connect VPC EIP NAT Gateway	You can use Direct Connect to connect your on-premises data center to the cloud and then buy a public NAT gateway to allow on-premises servers to access the Internet by setting SNAT rules or provide publicly accessible services by setting DNAT rules.
Allowing on-premises servers to access cloud services	Allowing On-Premises Servers to Access Cloud Services Using Direct Connect and VPC Endpoint	Direct Connect VPC Endpoint	You can create a connection to connect your on-premises data center to the cloud and then use VPC Endpoint to access cloud services over a private network. This enables faster access and reduces costs.