Red Hat Virtualization

Objectives

After completing this section, you should be able to configure hosts to use available logical networks.

Adding Logical Networks to RHV-H Hosts

In the previous section, you learned how to create logical networks to separate different types of network traffic. This section describes the procedures needed to implement the logical networks on cluster hosts. Use caution when performing this type of reconfiguration of the RHV environment, as a misstep might make your RHV-H host nonoperational.

Assigning Logical Networks

When a logical network is created, it is automatically attached to all clusters in the data center, unless you specify otherwise. If a cluster has at least one associated RHV-H host, the network's state is marked Non Operational until the logical network is attached to a physical interface on each cluster host. This is because the RHV-H host network configuration must be modified to attach the logical network to a physical network interface. When the attachment is complete, the logical network state becomes Operational.

Figure 6.2: Non Operational network state

After creating a new data center logical network, assign it to network interfaces on cluster hosts. For a required logical network to become active for a cluster, you must assign it to every RHV-H host in the cluster.

Optional networks, however, become operational immediately. A cluster host may use an optional logical network only when that network is associated with a network interface on that host.

To assign a logical network to an RHV-H host:

From the Hosts page, click the host name to which you will attach a network. On the upper menu bar, click the Network Interfaces tab to list the host's NICs. Click the Setup Host Networks button to open the Setup Host Networks window. Dragging a logical network listed under Unassigned Logical Networks and dropping it on a specific interface row will assign that network to the chosen interface.

Figure 6.3: Assigning a network to a host NIC

While still in the Setup Host Networks window, click the pencil icon at the right of a row of icons in a logical network box to open the Edit Management Network window for setting network parameters.

Figure 6.4: Viewing or Editing a Logical Network's Parameters

The window displays the network name. You can modify the boot protocol, and the IP address, netmask, and gateway when using static addressing. View the optional tabs for this network's IPv6, QoS, and DNS configuration.

Automating Attachment Using Labels

In a large RHV environment with multiple RHV-H hosts, it can be difficult to manually assign logical networks to host interfaces when the network design is changed. To help, Network labels can make assignments of logical networks to host vNICs simpler, by having RHV automatically assign new logical networks to hosts, or existing logical networks to new hosts, by matching up the labels assigned to each.

A network label is an arbitrary text string (using only upper and lowercase, underscores, or hyphens) that is set on a logical network, or a host physical interface. If cluster hosts have assigned labels on their interfaces, and a new logical network with a same label is added to the cluster, the logical network is automatically assigned to the matching network interfaces. Setting a specific label on a new logical network, for example, causes an automatic environment-wide attachment of that network on all hosts. Conversely, removing a label from a logical network removes that logical network from all hosts with that label.

Multiple Logical Networks on a Labeled Host NIC

Two or more logical networks can have the same label, if they are to be assigned to the same host physical NICs. Attaching two or more logical networks to the same NIC requires the use of unique VLAN IDs on each logical network. For example, you could add the internal label to one network interface on each host. Then, create two logical networks (VLAN tag 10 one and VLAN tag 20 on the other) and use the internal label on both. When you click the OK button to complete each logical network, each will automatically be associated with the same labeled network interface on every host.

Use the Setup Host Networks page to assign labels. Above the Unassigned Logical Networks is the Labels button. Dragging the New_Label to a desired interface adds the label name.