Planning for networks

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A network represents a set of Layer 2 and 3 network specifications, such as how your network is subdivided with VLANs. It also provides information about the subnet mask, gateway, and other characteristics. When you are deploying an image, you choose one or more existing networks to apply to the new virtual machine. Setting up networks beforehand reduces the amount of information that you need to input during each deployment and helps to ensure a successful deployment.

The first selected network is the management network that provides the primary system default gateway address. You can add more networks to segregate and manage the network traffic.

Note: A maximum of 32 vNICs can be attached to a virtual machine.

Networking and Resource Monitoring and Control (RMC)

Several PowerVC features, such as live migration and dynamic LPAR, add or remove NIC, etc require an active RMC connection between the management console (HMC or the NovaLink partition) and the virtual machine. In a NovaLink environment, the system will try to use an internal virtual switch (named MGMTSWITCH) to provide the RMC connections. This internal management network requires that images be created with rsct 3.2.1.0-15216 or later. See Updating Reliable Scalable Cluster Technology (RSCT) packages for PowerVM® NovaLink for details.

When adding or editing a network, you can set the maximum transmission unit (MTU) size. This specifies the value that cloud-init configures on a virtual machine's interface during activation. If you want to set MTU for network interfaces, install the latest cloud-init packages. Only network administrators should set this value.
  • For Linux®, install the appropriate cloud-init RPM available at /opt/ibm/powervc/images/cloud-init.
  • For AIX®, install the cloud-init RPM from ftp://public.dhe.ibm.com/aix/freeSoftware/aixtoolbox/RPMS/ppc/cloudinit.

Projects

When a network is created, it is added to a specific project, but after creation they can be shared across projects. The original project is considered the network's primary project.
Note: For shared networks, ports are not shared. Therefore, only ibm-admin can see the IP Addresses tab in the user interface.

You can customize the network on the Networks page. For example, you can change the network to belong to multiple projects or you can change it from DHCP to static. To use a network across multiple projects, you can select the option from the Networks page.

IPv4

PowerVC can be installed on a system with IPv4 stack. PowerVC uses the default network interface, eth0. To use a different network interface, set the HOST_INTERFACE environment variable before running the install script. Otherwise, the installer auto-selects eth0 and uses whichever stack is set up for that interface. As long as connectivity exists, hosts and storage of either type can be registered and managed with PowerVC. That is, PowerVC can communicate with hosts and storage over IPv4 addresses.

Notes:
  • PowerVC version 2.1.0 does not support IPv6.
  • Make sure that the management system has DNS properly configured so that hostname and management IP are resolvable. You can check /etc/resolv.conf file whether correct DNS server information is provided and it is functional. If the hostname resolution does not happen, you can resolve it locally by mentioning the hostname and IP mapping in the /etc/hosts file as below:
    x.x.x.x hostname short_hostname
Table 1. Types of networking supported on PowerVC
IPv4 Support
Management Server Virtual Machine deployed by PowerVC
Yes Yes