3.9.6. Configuring a cluster with dual-stack networking

Procedure

1. Create a network with IPv4 and IPv6 subnets. The available address modes for the ipv6-ra-mode and ipv6-address-mode fields are: dhcpv6-stateful, dhcpv6-stateless, and slaac.

   참고

   The dualstack network MTU must accommodate both the minimum MTU for IPv6, which is 1280, and the OVN-Kubernetes encapsulation overhead, which is 100.

   참고

   DHCP must be enabled on the subnets.

2. Create the API and Ingress VIPs ports.
3. Add the IPv6 subnet to the router to enable router advertisements. If you are using a provider network, you can enable router advertisements by adding the network as an external gateway, which also enables external connectivity.

4. To configure IPv4 and IPv6 address endpoints for cluster nodes, edit the install-config.yaml file. The following is an example of an install-config.yaml file:

   Example install-config.yaml

   apiVersion: v1
   baseDomain: mydomain.test
   compute:
   - name: worker
     platform:
       openstack:
         type: m1.xlarge
     replicas: 3
   controlPlane:
     name: master
     platform:
       openstack:
         type: m1.xlarge
     replicas: 3
   metadata:
     name: mycluster
   networking:
     machineNetwork: 

   1

   
     - cidr: "192.168.25.0/24"
     - cidr: "fd2e:6f44:5dd8:c956::/64"
     clusterNetwork: 

   2

   
     - cidr: 10.128.0.0/14
       hostPrefix: 23
     - cidr: fd01::/48
       hostPrefix: 64
     serviceNetwork: 

   3

   
     - 172.30.0.0/16
     - fd02::/112
   platform:
     openstack:
       ingressVIPs: ['192.168.25.79', 'fd2e:6f44:5dd8:c956:f816:3eff:fef1:1bad'] 

   4

   
       apiVIPs: ['192.168.25.199', 'fd2e:6f44:5dd8:c956:f816:3eff:fe78:cf36'] 

   5

   
       controlPlanePort: 

   6

   
         fixedIPs: 

   7

   
         - subnet: 

   8

   
             name: subnet-v4
             id: subnet-v4-id
         - subnet: 

   9

   
             name: subnet-v6
             id: subnet-v6-id
         network: 

   10

   
           name: dualstack
           id: network-id

   1 2 3

   You must specify an IP address range for both the IPv4 and IPv6 address families.

   4

   Specify the virtual IP (VIP) address endpoints for the Ingress VIP services to provide an interface to the cluster.

   5

   Specify the virtual IP (VIP) address endpoints for the API VIP services to provide an interface to the cluster.

   6

   Specify the dual-stack network details that are used by all of the nodes across the cluster.

   7

   The CIDR of any subnet specified in this field must match the CIDRs listed on networks.machineNetwork.

   8 9

   You can specify a value for either name or id, or both.

   10

   Specifying the network under the ControlPlanePort field is optional.

   Alternatively, if you want an IPv6 primary dual-stack cluster, edit the install-config.yaml file following the example below:

   Example install-config.yaml

   apiVersion: v1
   baseDomain: mydomain.test
   compute:
   - name: worker
     platform:
       openstack:
         type: m1.xlarge
     replicas: 3
   controlPlane:
     name: master
     platform:
       openstack:
         type: m1.xlarge
     replicas: 3
   metadata:
     name: mycluster
   networking:
     machineNetwork:
     - cidr: "fd2e:6f44:5dd8:c956::/64"
     - cidr: "192.168.25.0/24"
     clusterNetwork:
     - cidr: fd01::/48
       hostPrefix: 64
     - cidr: 10.128.0.0/14
       hostPrefix: 23
     serviceNetwork:
     - fd02::/112
     - 172.30.0.0/16
   platform:
     openstack:
       ingressVIPs: ['fd2e:6f44:5dd8:c956:f816:3eff:fef1:1bad', '192.168.25.79']
       apiVIPs: ['fd2e:6f44:5dd8:c956:f816:3eff:fe78:cf36', '192.168.25.199']
       controlPlanePort:
         fixedIPs:
         - subnet:
             name: subnet-v6
             id: subnet-v6-id
         - subnet:
             name: subnet-v4
             id: subnet-v4-id
         network:
           name: dualstack
           id: network-id

   • networking.machineNetwork, networking.clusterNetwork, and networking.serviceNetwork specify IP address ranges for both the IPv4 and IPv6 address families.
   • platform.openstack.ingressVIPs specifies the virtual IP (VIP) address endpoints for the Ingress VIP services to give an interface to the cluster.
   • platform.openstack.apiVIPs specifies the virtual IP (VIP) address endpoints for the API VIP services to give an interface to the cluster.
   • platform.openstack.controlPlanePort specifies the dual-stack network details that all the nodes across the cluster use.
   • platform.openstack.controlPlanePort.fixedIPs specifies the subnets for the control plane port. The CIDR of any subnet specified in this field must match the CIDRs listed on networking.machineNetwork.
   • platform.openstack.controlPlanePort.fixedIPs[].subnet specifies each subnet. You can specify a value for either name or id, or both.

   • platform.openstack.controlPlanePort.network specifies the network. Specifying the network under the controlPlanePort field is optional.

     참고

     When using an installation host in an isolated dual-stack network, the IPv6 address may not be reassigned correctly upon reboot.

     To resolve this problem on Red Hat Enterprise Linux (RHEL) 8, create a file called /etc/NetworkManager/system-connections/required-rhel8-ipv6.conf that contains the following configuration:

     [connection]
     type=ethernet
     [ipv6]
     addr-gen-mode=eui64
     method=auto

     To resolve this problem on RHEL 9, create a file called /etc/NetworkManager/conf.d/required-rhel9-ipv6.conf that contains the following configuration:

     [connection]
     ipv6.addr-gen-mode=0

     After you create and edit the file, reboot the installation host.

     참고

     The ip=dhcp,dhcp6 kernel argument, which is set on all of the nodes, results in a single Network Manager connection profile that is activated on multiple interfaces simultaneously. Because of this behavior, any additional network has the same connection enforced with an identical UUID. If you need an interface-specific configuration, create a new connection profile for that interface so that the default connection is no longer enforced on it.