Network configuration

Steps to configure the Red Hat® OpenShift® network and storage network. Use the defaults as is and customize only for any special CIDRs network requirements.

About this task

The Network settings page shows the OpenShift network to setup OpenShift and the storage configuration for the internal storage network of IBM Fusion. You can use the default values in this page and customize values only whenever you have specific network requirements. The OpenShift network section allows you to override the default network CIDRs, which might collide with the data center networks. Also, it provides the flexibility to choose your own range during network planning.
Important:
  • If you choose to edit the default values, ensure you remember the following points:
    • The CIDRs defined for the OpenShift network and Storage network do not overlap.
    • Each CIDR is large enough to handle nodes and workloads.
    • All IPs are unused by other systems on the network.
  • For high-availability multi rack is only supported with Data Foundation storage and not with Global Data Platform.

Procedure

  1. For Metro-DR setup, select whether it is the First cluster or Second cluster.
    Note: Metro-DR solution is only supported on Global Data Platform storage.
    If it is the second cluster, enter the value for Network configuration snippet:
    1. Log in to the user interface of the first cluster.
    2. Go to Disaster Reovery > Overview.
    3. In the Get started section, copy the network snippet.
    4. Go back to the installation page of the second cluster and paste it in Network configuration.
    During the Metro-DR stretch cluster installation on a secondary site, enable ping on ports 1191 and 12345. For more information about ports that must be enabled with pings, see IBM Storage Scale port usage.
  2. In the OpenShift network section, enter the following network configuration for Red Hat OpenShift.
    Important:
    • 100.64.0.0/16 is reserved for v4InternalSubnet by OVN and must not be used for CIDR in OpenShift Container Platform installation.
    • Use unique network values for Metro-DR clusters. The following values are pre-populated with unique values. If you want to change these values, ensure that the network setting used between the two Metro-DR sites are not duplicated.
    1. Enter Pod network CIDR. It is the IP address pools from which pod IP addresses are allocated. The default value is 10.128.0.0/14.
      Note: The Pod network CIDR must be different between site 1 and site 2 of Metro-DR.
    2. Enter Pod network Host Prefix. It is the subnet prefix length to assign to each individual node.

      For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given CIDR. A hostPrefix value of 23 provides 510 (2^(32 - 23) - 2) pod IP addresses. The default value is 23.

    3. Enter Service network CIDR. It is the IP address pool for the services. The default value is 172.30.0.0/16.
      Note: The Service network CIDR must be different between site 1 and site 2 of Metro-DR.
    4. In the Network MTU section, select either of the following values:
      • 9000 MTU is recommended option to maximize performance of features like Hosted Control Plane.
      • 1500 MTU is the default option for older switches to connect IBM Fusion HCI System to external networks. Check with you network administrator to understand whether this option is supported.
      Important: Ensure that the MTU setting is the same for both clusters in a Metro-DR relationship. The chosen MTU must be same on the complete network infrastructure where the traffic from or to is expected in the cluster.
  3. In the Storage network section, enter the following network configuration details for the internal storage network:
    Note: The CIDR address, Gateway address, and IP address range must be unique across site 1 and site 2. This is only available in case of Global Data Platform.
    1. Enter CIDR address. It is the network subnet that is used for the multus additional storage network of the scale core pods. The default value is 192.168.128.0/18.

      The list of reserved CIDRs are 169.254.169.0/29 and100.88.0.0/16.

    2. For list of all reserved ranges, see Red Hat Documentation.
    3. Enter the Gateway address. It is the gateway address for the scale core Pods on the multus additional storage network that connects to the other site in a Metro-DR.
      Note: In Metro-DR, the gateway must be pre-configured in the customer data center.
    4. Enter the IP address range. It is the IP address pools from which scale core pod IP addresses are allocated for the multus additional storage network. The default range is 192.168.128.11 - 192.168.191.254.
    5. Click Next to go to the Custom certificate wizard page.