Creating an IPv4/IPv6 Dual-Stack Cluster in CCE

Overview

IPv6 addresses are used to deal with the problem of IPv4 address exhaustion. If a worker node (such as an ECS) in the current cluster uses IPv4, the node can run in dual-stack mode after IPv6 is enabled. Specifically, the node has both IPv4 and IPv6 addresses, which can be used to access the intranet or public network.

Application Scenarios

• If your application needs to provide Services for users who use IPv6 clients, you can use IPv6 EIPs or the IPv4 and IPv6 dual-stack function.
• If your application needs to both provide Services for users who use IPv6 clients and analyze the access request data, you can use only the IPv4 and IPv6 dual-stack function.
• If internal communication is required between your application systems or between your application system and another system (such as the database system), you can use only the IPv4 and IPv6 dual-stack function.

Constraints

• Clusters that support IPv4/IPv6 dual stack:

  Cluster Type	Cluster Network Model	Version	Remarks
  CCE cluster	Container tunnel network	v1.15 or later	IPv4/IPv6 dual stack will be generally available for clusters of v1.23. ELB dual stack is not supported.

• Worker nodes and master nodes in Kubernetes clusters use IPv4 addresses to communicate with each other.
• If the Service type is set to LoadBalancer, only IPv4 addresses are supported.
• Only one IPv6 address can be bound to each NIC.
• When IPv4/IPv6 dual stack is enabled for the cluster, DHCP unlimited lease cannot be enabled for the selected node subnet.
• If a dual-stack cluster is used, do not change the load balancer protocol version on the ELB console.

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.

• The basic operations for IPv4 and IPv6 dual-stack networks are the same as those for IPv4 networks. Only some parameters are different.

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 of the management console and select a region and a project.
3. Under Networking, select Virtual Private Cloud.
4. Click Create VPC.
5. Set the VPC and subnet parameters.

   When configuring a subnet, select Enable for IPv6 CIDR Block to automatically allocate an IPv6 CIDR block to the subnet. IPv6 cannot be disabled after the subnet is created. Currently, you are not allowed to specify a custom IPv6 CIDR block.

   Table 1 VPC configuration parameters

   Parameter	Description	Example Value
   Region	Specifies the desired 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.	-
   Name	VPC name.	vpc-ipv6
   IPv4 CIDR Block	Specifies the Classless Inter-Domain Routing (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 (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
   Tag (Advanced Settings)	Specifies the VPC tag, which consists of a key and value pair. You can add a maximum of ten tags for each VPC. The tag key and value must meet the requirements listed in Table 3.	Tag key: vpc_key1 Key value: vpc-01

   Table 2 Subnet parameters

   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.	AZ2
   Name	Specifies the subnet name.	subnet-ipv6
   IPv4 CIDR Block	Specifies the IPv4 CIDR block for the subnet. This value must be within the VPC CIDR range.	192.168.0.0/24
   IPv6 CIDR Block	Select Enable for IPv6 CIDR Block. An IPv6 CIDR block will be automatically assigned to the subnet. IPv6 cannot be disabled after the subnet is created. Currently, you are not allowed to specify a custom IPv6 CIDR block.	N/A
   Associated Route Table	Specifies the default route table to which the subnet will be associated. You can change the route table to a custom route table.	Default
   Advanced Settings
   Gateway	Specifies the gateway address of the subnet. This IP address is used to communicate with other subnets.	192.168.0.1
   DNS Server Address	By default, two DNS server addresses are configured. You can change them if necessary. When multiple IP addresses are available, separate them with a comma (,).	100.125.x.x
   DHCP Lease Time	Specifies 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. If a DHCP lease time is changed, the new lease automatically takes effect when half of the current lease time has passed. To make the change take effect immediately, restart the ECS or log in to the ECS to cause the DHCP lease to automatically renew. CAUTION: When IPv4/IPv6 dual stack is enabled for the cluster, DHCP unlimited lease cannot be enabled for the selected node subnet.	365 days or 300 hours
   Tag	Specifies the subnet tag, which consists of a key and value pair. You can add a maximum of ten tags to each subnet. The tag key and value must meet the requirements listed in Table 4.	Tag key: subnet_key1 Key value: subnet-01

   Table 3 VPC tag key and value requirements

   Parameter	Requirement	Example Value
   Tag key	Cannot be left blank. Must be unique in a VPC. Can contain a maximum of 36 characters. Can contain letters, digits, underscores (_), and hyphens (-).	vpc_key1
   Tag value	Can contain a maximum of 43 characters. Can contain letters, digits, underscores (_), periods (.), and hyphens (-).	vpc-01

   Table 4 Subnet tag key and value requirements

   Parameter	Requirement	Example Value
   Tag key	Cannot be left blank. Must be unique for each subnet. Can contain a maximum of 36 characters. Can contain letters, digits, underscores (_), and hyphens (-).	subnet_key1
   Tag value	Can contain a maximum of 43 characters. Can contain letters, digits, underscores (_), periods (.), and hyphens (-).	subnet-01

6. Click Create Now.

Step 2: Create a CCE Cluster

Step 3: Apply for a Shared Bandwidth and Adding an IPv6 Address to It

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

If you already have a shared bandwidth, you can add the IPv6 address to the shared bandwidth without applying for one.

Applying a Shared Bandwidth

1. Log in to the management console.
2. Click in the upper left corner of the management console and select a region and a project.
3. Choose Service List > Networking > Virtual Private Cloud.
4. In the navigation pane, choose Elastic IP and Bandwidth > Shared Bandwidths.
5. In the upper right corner, click Create Shared Bandwidth. On the displayed page, configure parameters following instructions.

   Table 5 Parameters

   Parameter	Description	Example Value
   Bandwidth	Specifies the shared bandwidth size in Mbit/s. The minimum bandwidth that can be purchased is 5 Mbit/s.	10
   Name	Specifies the name of the shared bandwidth.	Bandwidth-001

6. Click OK.

Adding an IPv6 Address to a Shared Bandwidth

1. On the shared bandwidth list page, locate the row containing the target shared bandwidth and click Add Public IP Address in the Operation column.
2. Add the IPv6 address to the shared bandwidth.
3. Click OK.

Verifying the Result

Log in to an ECS and ping an IPv6 address on the Internet to verify the connectivity. ping6 ipv6.baidu.com is used as an example here. The execution result is displayed in Figure 1.

Figure 1 Result verification