A virtual private cloud (VPC) is a private network deployed on Alibaba Cloud. You have full control over your VPC. For example, you can specify CIDR blocks, and configure route tables and gateways for your VPC. You can create a VPC, and then use Alibaba Cloud resources such as, Elastic Compute Service (ECS), ApsaraDB RDS, and Server Load Balancer (SLB) instances in the VPC. After you create a VPC, you can add secondary IPv4 CIDR blocks to it to expand the VPC. This topic describes how to work with VPCs.
Operations
Create a VPC
Before you create a VPC, you must plan your networks. For more information, see Plan and design a VPC.
View a VPC
Modify basic information about a VPC
You can modify the name and description about a VPC.
Add a secondary IPv4 CIDR block
Before you add a secondary IPv4 CIDR block, make sure that a VPC is created.
The IPv4 CIDR block that you configure when you create a VPC is the primary IPv4 CIDR block. After a VPC is created, the primary IPv4 CIDR block of the VPC cannot be modified. However, you can add a secondary IPv4 CIDR block to expand the VPC. After you add a secondary IPv4 CIDR block to the VPC, both the primary and secondary IPv4 CIDR blocks are in effect. You can create a vSwitch with the primary or a secondary IPv4 CIDR block. However, each vSwitch belongs to only one VPC CIDR block.
The system automatically adds a vSwitch route to the VPC route table when you create a vSwitch with the primary or a secondary IPv4 CIDR block. The destination CIDR block of a vSwitch route is the CIDR block with which the vSwitch is created. The CIDR block range cannot be the same as or larger than those of other routes in the route table of the VPC.
For example, you have added 172.16.0.0/16 to the VPC as a secondary IPv4 CIDR block. The VPC route table already contains Cloud Enterprise Network (CEN) routes (overlapping routing is enabled), and the destination CIDR block is 172.16.0.0/24. In this case, you cannot create a vSwitch with a CIDR block that is the same or larger than the CIDR block 172.16.0.0/24. However, you can create a vSwitch with 172.16.0.0/25 or a smaller CIDR block.

Delete a secondary IPv4 CIDR block
You can delete a secondary IPv4 CIDR block of a VPC. However, you cannot delete the primary IPv4 CIDR block of a VPC.
Before you delete a secondary IPv4 CIDR block, make sure that you have deleted the vSwitch that is created with the secondary IPv4 CIDR block. For more information, see Delete a vSwitch.
- Log on to the VPC console.
- In the top navigation bar, select the region where the VPC is deployed.
- On the VPCs page, find the VPC and click its ID.
- On the VPC Details page, click the CIDRs tab.
- On the CIDRs tab, find the secondary IPv4 CIDR block and click Delete in the Actions column.
- In the message that appears, click OK.
Delete a VPC
You can delete a VPC that you no longer need. After you delete a VPC, vRouters and route tables that are associated with the VPC are also deleted. Before you delete a VPC, make sure that the following requirements are met:
- No vSwitch exists in the VPC. If the VPC contains a vSwitch, you must delete the vSwitch before you delete the VPC. For more information, see Delete a vSwitch.
- No IPv6 gateway is associated with the VPC. If the VPC is associated with an IPv6 gateway, you must delete the IPv6 gateway before you delete the VPC.
- Log on to the VPC console.
- In the top navigation bar, select the region where the VPC is deployed.
- On the VPCs page, find the VPC that you want to manage, and click Delete in the Actions column.
- In the Delete VPC message, click OK.