If there is no available VPC and VSwitch to use when creating a cloud resource with the VPC network, you can choose to use the default VPC and VSwitch. A default VPC and VSwitch are created along with the creation of the instance. This document takes ECS as an example to introduce how to create a default VPC and VSwitch.

Background information

A region can only have one default VPC but many default VSwitches. Because VPC is a region-based resource while VSwitch is a zone-based resource. Each zone can have a default VSwitch. The properties of default VPC and VSwitch are as follows:
Default VPC Default VSwitch
The default VPC in each region is unique. The default VSwitch in each zone is unique.
The netmask for a default VPC is /16, such as 172.31.0.0/16, providing up to 65536 private IP addresses. The netmask for a default VSwitch is /20, such as 172.31.0.0/20, providing up to 4096 private IP addresses.
The default VPC does not take up the VPC quota. The default VSwitch does not take up the VSwitch quota.
The default VPC is created by the system, and all VPCs created by you are non-default VPCs. The default VSwitch is created by the system, and all VSwitches created by you are non-default VSwitches.
The operations and specifications for the default VPC and non-default VPCs are the same. The operations and specifications for the default VSwitch and non-default VSwitches are the same.

Procedure

  1. Log on to the ECS console.
  2. In the left-side navigation pane, click Instances and then click Create Instance.
  3. Select Advanced Purchase.
  4. On the Basic Configurations page, configure ECS instance and click Next: Networking.
  5. On the Networking page, select default VPC and the default VSwitch. Click Next: System Configurations.


  6. Configure the login credential and instance name, and click Create Order.

    After the instance is created, a default VPC and a default VSwitch will be created in the region.

    Figure 1. Default VPC


    Figure 2. Default VSwitch