A virtual private cloud (VPC) is a private network dedicated for your use. You have full control over your VPC, which you can define and customize by specifying the Classless Inter-domain Routing (CIDR) block, configuring route tables, and creating gateways. You can launch Apsara Stack resources such as Elastic Compute Service (ECS) instances, ApsaraDB for RDS (RDS) instances, and Server Load Balancer (SLB) instances in your VPC.
Furthermore, you can connect your VPC to other VPCs or on-premises networks to create a custom network environment. In this way, you can smoothly migrate applications and extend on-premises data centers to the cloud.
Each VPC consists of one VRouter, at least one private CIDR block, and one or more VSwitches.
Private CIDR block
When you create a VPC or a VSwitch, you must specify its private IP address range in the form of a CIDR block.
You can use the standard private CIDR blocks listed in the following table and their subsets as CIDR blocks for your VPCs. For more information, see Plan and design a VPC.
CIDR block Number of available private IP addresses (excluding those reserved by the system) 192.168.0.0/16 65,532 172.16.0.0/12 1,048,572 10.0.0.0/8 16,777,212
A VRouter is a hub that connects all VSwitches in a VPC and serves as a gateway between the VPC and other networks. After a VPC is created, a VRouter is automatically created for the VPC. Each VRouter is associated with a route table.
For more information, see Overview.
A VSwitch is a basic network component that connects different cloud resources in a VPC. After you create a VPC, you can create VSwitches to partition your VPC into multiple subnets. VSwitches within a VPC can communicate with each other over the private network. You can deploy your applications in VSwitches that belong to different zones to improve service availability.
For more information, see VSwitches.