Setting up an IPv6 Network

Scenarios

This topic describes how to create a VPC with an IPv6 CIDR block and create an ECS with an IPv6 address in the VPC, so that the ECS can access the Internet using the IPv6 address.

Application Scenarios of IPv4/IPv6 Dual Stack

Step 1: Create a VPC

Before creating your VPCs, determine how many VPCs, the number of subnets, and what IP address ranges you will need.

Perform the following operations to create a VPC named vpc-ipv6 and its default subnet named subnet-ipv6.

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.
4. Set the VPC and subnet parameters.

   When configuring a subnet, select Enable for IPv6 CIDR Block so that the system will automatically allocate an IPv6 CIDR block to the subnet. IPv6 cannot be disabled after the subnet is created. Currently, customizing IPv6 CIDR block is not supported.

   Table 2 VPC parameter descriptions

   Parameter	Description	Example Value
   Region	Select the region nearest to you to ensure the lowest latency possible.	-
   Name	The VPC 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.	VPC-test
   IPv4 CIDR Block	The CIDR block of the VPC. The CIDR block of a subnet can be the same as the CIDR block for the VPC (for a single subnet in the VPC) or a subset of the CIDR block for the VPC (for multiple subnets in the VPC). The following CIDR blocks are supported: 10.0.0.0/8-24 172.16.0.0/12-24 192.168.0.0/16-24	192.168.0.0/16
   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. For details about creating and managing enterprise projects, see the Enterprise Management User Guide.	default
   Advanced Settings	Click the drop-down arrow to set advanced VPC parameters, including tags.	Retain the default settings.
   Tag	The VPC tag, which consists of a key and value pair. You can add a maximum of 10 tags to each VPC.	Key: vpc_key1 Value: vpc-01

   Table 3 Subnet parameter descriptions

   Parameter	Description	Example Value
   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: A VPC can have subnets that are in different AZs. For example, a VPC can have subnet A in AZ 1, and subnet B in AZ 3. A cloud resource and its subnet can be in different AZs. For example, a cloud server in AZ 1 can use a subnet in AZ 3.	AZ1
   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-01
   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. 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 to which the subnet will be associated. You can change the route table to a custom route table on the Subnets page.	Default
   Advanced Settings	Click the drop-down arrow to set advanced settings for the subnet, including Gateway and DNS Server Address.	Retain the default settings.
   Gateway	The gateway address of the subnet. This IP address is used to communicate with other subnets.	192.168.0.1
   DNS Server Address	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. A maximum of two DNS server IP addresses can be configured. Multiple IP addresses must be separated using commas (,).	100.125.x.x
   DHCP Lease Time	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. Unit: Day or hour 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.	-
   NTP Server Address	The IP address of the NTP server. This parameter is optional. You can configure the NTP server IP addresses to be added to the subnet as required. The IP addresses are added in addition to the default NTP server addresses. If you do not specify this parameter, no additional NTP server IP addresses will be added. Enter a maximum of four valid IP addresses, and separate multiple IP addresses with commas. Each IP address must be unique. 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
   Tag	The subnet tag, which consists of a key and value pair. You can add a maximum of 10 tags to each subnet.	Key: subnet_key1 Value: subnet-01
   Description	Supplementary information about the subnet. This parameter is optional. The subnet description can contain a maximum of 255 characters and cannot contain angle brackets (< or >).	N/A

5. Click Create Now.

Step 2: Buy an ECS

Configure the network for the ECS as follows:

• Network:
  • Select the created VPC vpc-ipv6.
  • Select the created subnet subnet-ipv6.
  • Select Self-assigned IPv6 address.
    

    Select Self-assigned IPv6 address during ECS creation to assign an IPv6 address to the ECS. Otherwise, the IPv4/IPv6 dual-stack network cannot be used.

  • Shared Bandwidth
    • If you select Do not configure, only IPv6 communication in a VPC is supported. If you want to enable Internet access, you need to perform operations in (Optional) Step 3: Buy a Shared Bandwidth and Add the IPv6 Address to It.
    • If you assign a shared bandwidth or select an existing shared bandwidth, the ECS can use the IPv6 address to access the Internet after the configuration is complete.
• Security Group: Select the default security group Sys-default. The default security group rule allows all outgoing IPv4 and IPv6 data packets and denies all inbound data packets. ECSs in the same security group can access each other without the need to add rules. You can also create a security group and add rules to it.
• EIP: Select Not required.

After the ECS is created, you can view the assigned IPv6 address on the ECS details page. You can also log in to the ECS and run the ifconfig command to view the assigned IPv6 address.

(Optional) Dynamically Assigning IPv6 Addresses

If an IPv6 address fails to be automatically assigned or the selected image does not support the function of automatic IPv6 address assignment, manually obtain the IPv6 address by referring to .

If an ECS is created from a public image:

Before enabling dynamic IPv6 address assignment for a Linux public image, check whether IPv6 is supported and then check whether dynamic IPv6 address assignment has been enabled. Currently, all Linux public images support IPv6, and dynamic IPv6 address assignment is enabled for Ubuntu 16 by default. You do not need to configure dynamic IPv6 address assignment for the Ubuntu 16 OS. For other Linux public images, you need to enable this function.

(Optional) Step 3: Buy a Shared Bandwidth and Add the IPv6 Address to It

By default, an IPv6 address can only be used for private network communication. If you want to use this IPv6 address to access the Internet or want it to be accessed by IPv6 clients on the Internet, you need to buy a shared bandwidth and add the IPv6 address to it.

If you already have a shared bandwidth, add the IPv6 address to the shared bandwidth.

Buying a Shared Bandwidth

1. Log in to the management console.
2. Click in the upper left corner and select the desired region and project.
3. Click in the upper left corner and choose Network > Elastic IP.
4. In the navigation pane on the left, choose Elastic IP and Bandwidth > Shared Bandwidths.
5. In the upper right corner, click Assign Shared Bandwidth. On the displayed page, configure parameters as prompted.

   Table 4 Parameter descriptions

   Parameter	Description	Example Value
   Region	Regions are geographic areas that are physically isolated from each other. The networks inside different regions are not connected to each other, so resources cannot be shared across different regions. For lower network latency and faster access to your resources, select the region nearest you.	N/A
   Billed By	The billing method for the shared bandwidth. You can specify a shared bandwidth to be billed by bandwidth.	Bandwidth
   Bandwidth	The bandwidth size in Mbit/s. The maximum bandwidth can be 300 Mbit/s.	10
   Name	The name of the shared bandwidth.	Bandwidth-001
   Enterprise Project	The enterprise project that the EIP belongs to. An enterprise project facilitates project-level management and grouping of cloud resources and users. The name of the default project is default. For details about creating and managing enterprise projects, see the Enterprise Management User Guide.	default

6. Click Create Now.

Adding the IPv6 Address to a Shared Bandwidth

1. On the Shared Bandwidths page, click Add Public IP Address in the Operation column.
   Figure 1 Adding an IPv6 address to a shared bandwidth
   
2. Add the IPv6 address to the shared bandwidth.
   Figure 2 Adding an IPv6 address to a shared bandwidth
   
3. Click OK.

Verifying the Result

Log in to the ECS and ping an IPv6 address on the Internet to verify network connectivity. Figure 3 shows an example command output.

Log in to the ECS using SSH or the RDP file through the EIP.

Figure 3 Verification