You can connect a virtual private cloud (VPC) to the Internet, another VPC, or a data center.
Enable Internet access
|Static public IP address||When you create an ECS instance in a VPC, you can specify whether you want the system to assign a public IPv4 address to the ECS instance. The ECS instance can use the public IP address to communicate with the Internet. |
You cannot disassociate the public IP address from the ECS instance. However, you can convert the public IP address to an EIP. For more information, see Convert the static public IP address of an ECS instance in a VPC to an EIP.
You can purchase data transfer plans for an ECS instance that is assigned a public IP address. You can also purchase EIP bandwidth plans for an ECS instance after you convert the public IP address of the ECS instance to an EIP. For more information, see What is an EIP bandwidth plan? and What is a data transfer plan ?.
|EIP||You can associate EIPs with or disassociate EIPs from ECS instances anytime. ECS instances in a VPC can use EIPs in SNAT entries to access the Internet and use EIPs in DNAT entries to provide Internet-facing services.|
You can associate EIPs with or disassociate EIPs from ECS instances anytime.
You can use EIP bandwidth plans and data transfer plans to reduce the cost of data transfer over the Internet.
|Internet NAT Gateway||ECS instances in a VPC can use SNAT entries to access the Internet and use DNAT entries to provide Internet-facing services. |
Note Internet NAT gateways do not provide load balancing services. To balance the loads of ECS instances, use SLB.
|An Internet NAT gateway allows multiple ECS instances in a VPC to communicate with the Internet. However, each EIP can be used by only one ECS instance.|
SLB provides load balancing services at Layer 4 and Layer 7. You can specify the ports on which SLB listens to distribute requests from the Internet to ECS instances. Alibaba Cloud provides two types of SLB instances: CLB and ALB.
Note SLB does not support SNAT. ECS instances deployed in a VPC cannot access the Internet through SLB.
|SLB supports DNAT. Each port on an SLB instance can be mapped to one or more ECS instances. |
SLB distributes network traffic across multiple ECS instances to prevent single points of failure. This improves the availability of application systems.
After you associate an EIP with an SLB instance, you can purchase EIP bandwidth plans and data transfer plans to reduce costs.
You can establish connections among VPCs that belong to different regions and Alibaba Cloud accounts.
For more information, see Create a VPC connection.
|VPC peering connections|
A VPC peering connection is a private network connection between two VPCs. You can enable two VPCs to communicate with each other by establishing a VPC peering connection. You can establish a VPC peering connection between VPCs that belong to the same Alibaba Cloud account or different Alibaba Cloud accounts. In addition, the VPCs can be deployed in the same region or in different regions.
For more information, see Overview of VPC peering connections.
|VPN Gateway||You can establish an IPsec-VPN connection between two VPCs for encrypted data transmission. |
For more information, see Establish IPsec-VPN connections between two VPCs.
Connect a data center to a VPC
|Express Connect||You can use an Express Connect circuit to connect a data center to a VPC. |
For more information, see What is a connection over an Express Connect circuit?.