Virtual Private Cloud (VPC) is a private network established in Alibaba Cloud. VPCs are logically isolated from other virtual networks in Alibaba Cloud.
VPC is a private network dedicated to you in Alibaba Cloud. You have full control over your VPC, such as specifying its IP address range, and configuring route tables and network gateways. You can also use Alibaba Cloud resources such as ECS, RDS, and SLB in your own VPC.
Additionally, you can connect a VPC to another VPC or to an on-premises IDC network to form an on-demand network environment, which allows you to smoothly migrate applications to Alibaba Cloud and expand the on-premises IDC.
VRouter is the hub of a VPC. As an important component of a VPC, it connects VSwitches in a VPC and serves as the gateway connecting the VPC with other networks. After you successfully create a VPC, the system automatically creates a VRouter, which is associated with a route table. For more information, see Routes.
VSwitch is a basic network device of a VPC and used to connect different cloud product instances. After creating a VPC, you can further segment your virtual private network to one or more subnets by creating VSwitches. The VSwitches within a VPC are interconnected. Therefore, you can deploy different an application in the different VSwitches of different zones to improve the service availability.
When creating a VPC or a VSwitch, you must specify the private IP address range in the form of Classless Inter-Domain Routing (CIDR) block. For more information, see Classless Inter-Domain Routing.
You can use any of the following standard CIDR blocks and their subnets as the IP address range of the VPC. After a VPC is created, you cannot change its CIDR block. We recommend that you use a large CIDR block to avoid subsequent expansion.
|CIDR block||Number of available private IPs (system reserved ones not included)|
The CIDR block of a VSwitch can be the same as the CIDR block of the VPC to which it belongs or a subnet of the VPC CIDR block. The size of the subnet mask for the VSwitch CIDR block can be /16 to /29.
For more information, see Plan and design VPC.