Creating a VPC with a Subnet

Virtual Private Cloud (VPC) allows you to provision logically isolated virtual private networks for cloud resources, such as cloud servers, containers, and databases.

You can create a VPC, specify a CIDR block, and create one or more subnets for the VPC. A VPC comes with a default route table that enables subnets in the VPC to communicate with each other.

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

   The Virtual Private Cloud page is displayed.

3. Click Create VPC.

   The Create VPC page is displayed.

4. On the Create VPC page, configure parameters for the VPC and subnets as prompted.

   You can click to add more subnets.

   Table 1 VPC parameter descriptions

   Parameter	Description	Example Value
   Region	Regions are geographic areas isolated from each other. For low network latency and quick resource access, select the region nearest to where your services will be accessed.	-
   Name	The VPC name. The name: Can contain 1 to 64 characters. Can contain letters, digits, underscores (_), hyphens (-), and periods (.).	vpc-test
   IPv4 CIDR Block	The IPv4 CIDR block of the VPC. Consider the following when specifying a CIDR block: Number of IP addresses: Reserve enough IP addresses for subsequent business growth. IP address ranges: Avoid IP address conflicts if you need to connect a VPC to an on-premises data center or connect two VPCs. When you create a VPC, we recommend that you use the private IPv4 address ranges specified in RFC 1918 as the CIDR block: 10.0.0.0/8–24: The IP addresses are from 10.0.0.0 to 10.255.255.255, and the netmask ranges from 8 to 24. 172.16.0.0/12–24: The IP addresses are from 172.16.0.0 to 172.31.255.255, and the netmask ranges from 12 to 24. 192.168.0.0/16–24: The IP addresses are from 192.168.0.0 to 192.168.255.255, and the netmask ranges from 16 to 24. In addition to the preceding addresses, you can create a VPC with a publicly routable CIDR block that falls outside of the private IPv4 address ranges specified in RFC 1918. However, the following system and public reserved addresses must be excluded: Reserved system CIDR blocks 100.64.0.0/10 214.0.0.0/7 198.18.0.0/15 169.254.0.0/16 Reserved public CIDR blocks 0.0.0.0/8 127.0.0.0/8 240.0.0.0/4 For details about VPC planning, see VPC Network Planning Suggestions.	10.0.0.0/8
   Enterprise Project	The enterprise project to which the VPC belongs. An enterprise project facilitates project-level management and grouping of cloud resources and users. The name of the default project is default.	default
   Advanced Settings (Optional) > Tag	The VPC tag. Click to expand the configuration area and set this parameter. Add tags to help you quickly identify, classify, and search for your VPCs. For details, see Managing VPC Tags.	Key: vpc_key1 Value: vpc-01
   Advanced Settings (Optional) > Description	Supplementary information about the VPC. Click to expand the configuration area and set this parameter. Enter the description about the VPC in the text box as required. The description can contain a maximum of 255 characters and cannot contain angle brackets (< or >).	N/A

   Table 2 Subnet parameter descriptions

   Parameter	Description	Example Value
   Subnet Name	The subnet name. The name: Can contain 1 to 64 characters. Can contain letters, digits, underscores (_), hyphens (-), and periods (.).	subnet-01
   IPv4 CIDR Block	The IPv4 CIDR block of the subnet. A subnet is a unique CIDR block with a range of IP addresses in a VPC. Comply with the following principles when planning subnets: Planning CIDR block size: After a subnet is created, the CIDR block cannot be changed. You need to plan the CIDR block in advance based on the number of IP addresses required by your service. The subnet CIDR block cannot be too small. Ensure that the number of available IP addresses in the subnet meets service requirements. The first and last three addresses in a subnet are reserved for system use. For example, in subnet 10.0.0.0/24, 10.0.0.1 is the gateway address, 10.0.0.253 is the system interface address, 10.0.0.254 is used by DHCP, and 10.0.0.255 is the broadcast address. The subnet CIDR block cannot be too large, either. If you use a CIDR block that is too large, you may not have enough CIDR blocks from the VPC available for new subnets, which can be a problem when you want to scale out services. Avoiding subnet CIDR block conflicts: Avoid CIDR block conflicts if you need to connect two VPCs or connect a VPC to an on-premises data center.	10.0.0.0/24
   IPv6 CIDR Block	After the IPv6 function is enabled, 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.	-
   Associated Route Table	The default route table with which the subnet will be associated. A route table contains a set of routes that are used to control the traffic routing for your subnets in a VPC. A default route table automatically comes with a VPC. Subnets in the VPC are automatically associated with the default route table. The default route table ensures that subnets in a VPC can communicate with each other.	-
   Advanced Settings (Optional) > Gateway	The gateway address of the subnet. Click to expand the configuration area and set this parameter. Retain the default value unless there are special requirements.	10.0.0.1
   Advanced Settings (Optional) > DNS Server Address	The DNS server addresses. Click to expand the configuration area and set this parameter. DNS server addresses allow ECSs in a VPC subnet to communicate with each other using private domain names. You can also directly access cloud services through private DNS servers. If you want to use other public DNS servers for resolution, you can change the default DNS server addresses. Changing the default DNS server addresses may cause communication failures in the subnet.	100.125.x.x
   Advanced Settings (Optional) > Domain Name	Click to expand the configuration area and set this parameter. You can enter multiple domain name suffixes separated by spaces. A domain name can contain one or more character strings separated by periods (.). Each character string can contain a maximum of 63 characters. (For example, domain name test.com contains two character strings: test and com.) The total length of the domain name cannot exceed 254 characters. To access a domain name, you only need to enter the domain name prefix. ECSs in the subnet automatically match the configured domain name suffix. If the domain names are changed, ECSs newly added to this subnet will use the new domain names. If an existing ECS in this subnet needs to use the new domain names, restart the ECS or run a command to restart the DHCP Client service or network service.	test.com
   Advanced Settings (Optional) > IPv4 DHCP Lease Time	The period during which a client can use an IP address automatically assigned by the DHCP server. Click to expand the configuration area and set this parameter. The period during which a client can use an IP address automatically assigned by the DHCP server. After the lease time expires, a new IP address will be assigned to the client. After you change the DHCP lease time on the console, the change is applied automatically when the DHCP lease of an instance (such as ECS) is renewed. You can wait for the system to renew the lease or manually renew the lease. Renewing lease will not change the IP address used by the instance. If you want the new lease time to take effect immediately, manually renew the lease or restart the ECS.	-
   Advanced Settings (Optional) > NTP Server Address	The IP address of the NTP server. Click to expand the configuration area and set this parameter. If you want to add NTP server addresses for a subnet, you can specify NTP Server Address. The IP addresses are added in addition to the default NTP server addresses. If you add or change the NTP server addresses of a subnet, you need to renew the DHCP lease for or restart all the ECSs in the subnet to make the change take effect immediately. If the NTP server addresses have been cleared out, restarting the ECSs will not help. You must renew the DHCP lease for all ECSs to make the change take effect immediately.	192.168.2.1
   Advanced Settings (Optional) > Tag	The subnet tag. Click to expand the configuration area and set this parameter. Add tags to help you quickly identify, classify, and search for your subnets. For details, see Managing Subnet Tags.	Key: subnet_key1 Value: subnet-01
   Advanced Settings (Optional) > Description	Supplementary information about the subnet. Click to expand the configuration area and set this parameter. Enter the description about the subnet in the text box as required. The description can contain a maximum of 255 characters and cannot contain angle brackets (< or >).	N/A

5. Click Create Now.

   Return to the VPC list and view the new VPC.