Virtual Private Cloud (VPC) allows you to create a custom private virtual network on Alibaba Cloud. VPCs are logically isolated from each other. You can fully control your VPC, such as specifying CIDR blocks and configuring route tables and gateways. You can also create and manage Alibaba Cloud resources in your VPC, such as Elastic Compute Service (ECS) instances, Server Load Balancer (SLB) instances, and ApsaraDB RDS instances.
- Private CIDR blocksWhen you create a VPC and a vSwitch, you must specify a private IP address range for the VPC in CIDR notation. You can specify one of the standard private CIDR blocks that are listed in the following table as the private CIDR block of a VPC, or use a custom CIDR block. For more information, see Plan networks.
CIDR block Description 192.168.0.0/16 Number of available private IP addresses (excluding IP addresses reserved by the system): 65,532 172.16.0.0/12 Number of available private IP addresses (excluding IP addresses reserved by the system): 1,048,572 10.0.0.0/8 Number of available private IP addresses (excluding IP addresses reserved by the system): 16,777,212 Custom CIDR block You can use a custom CIDR block, except 100.64.0.0/10, 220.127.116.11/4, 127.0.0.0/8, 169.254.0.0/16, and their subsets.
A vRouter is a virtual router that connects all vSwitches in a VPC. A vRouter serves as a gateway between a VPC and other networks. After you create a VPC, a vRouter is automatically created for the VPC. A vRouter is associated with at least one route table. For more information about route tables, see Route table overview.
A vSwitch is a basic network device of VPC. You can use a vSwitch to connect different cloud resources. After you create a VPC, you can create vSwitches to divide the VPC into one or more subnets. vSwitches that are in the same VPC can communicate with each other. To improve service availability, you can deploy your applications in vSwitches that belong to different zones. For more information about vSwitches, see Create and manage a vSwitch.
Instances that reside in VPCs can connect to the Internet, other VPCs, and local data centers. Alibaba Cloud provides various solutions to meet the requirements of the connections. For more information, see Manage VPC connections.
Before you use a VPC, you must plan your VPC based on your business requirements. For more information, see Plan networks.