Help Center/ Virtual Private Cloud/ User Guide (Ankara Region)/ Getting Started/ Configuring a VPC for ECSs That Access the Internet Using EIPs/ Step 2: Create a Subnet for the VPC
Updated on 2024-04-15 GMT+08:00
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Step 2: Create a Subnet for the VPC

Scenarios

A VPC comes with a default subnet. If the default subnet cannot meet your requirements, you can create one.

Procedure

  1. Log in to the management console.
  1. Click in the upper left corner and choose Network > Virtual Private Cloud.

    The Virtual Private Cloud page is displayed.

  2. In the navigation pane on the left, choose Virtual Private Cloud > Subnets.
  3. Click Create Subnet.

    The Create Subnet page is displayed.

  4. Set the parameters as prompted.
    Table 1 Parameter descriptions

    Parameter

    Description

    Example Value

    VPC

    The VPC for which you want to create a subnet.

    -

    AZ

    An AZ is a geographic location with independent power supply and network facilities in a region. AZs are physically isolated, and AZs in the same VPC are interconnected through an internal network.

    Note the following when you select an AZ:
    • Subnets in a VPC can be in different AZs. For example, a VPC can have a subnet in AZ 1, and another subnet in AZ 3.
    • A cloud resource can be in a different AZ from its subnet. For example, a cloud server in AZ 1 can be in a subnet in AZ 3.

    sa-fb-1

    Name

    The subnet name.

    The name can contain a maximum of 64 characters, which may consist of letters, digits, underscores (_), hyphens (-), and periods (.). The name cannot contain spaces.

    Subnet

    IPv4 CIDR Block

    The CIDR block for the subnet. This value must be within the VPC CIDR block.

    192.168.0.0/24

    IPv6 CIDR Block

    Specifies whether to set IPv6 CIDR Block to Enable.

    If you select this option, the system automatically assigns an IPv6 CIDR block to the created subnet. Currently, the IPv6 CIDR block cannot be customized. IPv6 cannot be disabled after the subnet is created.

    -

    Gateway

    The gateway address of the subnet.

    192.168.0.1

    DNS Server Address

    By default, two DNS server addresses are configured. You can change them if necessary. Multiple IP addresses must be separated using commas (,).

    100.125.x.x
  5. Click OK.

Precautions

After a subnet is created, some reserved IP addresses cannot be used. For example, in a subnet with CIDR block 192.168.0.0/24, the following IP addresses are reserved:

  • 192.168.0.0: Network ID. This address is the beginning of the private IP address range and will not be assigned to any instance.
  • 192.168.0.1: Gateway address.
  • 192.168.0.253: Reserved for the system interface. This IP address is used by the VPC for external communication.
  • 192.168.0.255: Network broadcast address.

If you configured the default settings under Advanced Settings during subnet creation, the reserved IP addresses may be different from the default ones, but there will still be five of them. The specific addresses depend on your subnet settings.