⁠6.3. Logical Network Tasks

6.3.1. Using the Networks Tab
6.3.2. Creating a New Logical Network in a Data Center or Cluster
6.3.3. Editing a Logical Network
6.3.4. Explanation of Settings and Controls in the New Logical Network and Edit Logical Network Windows
6.3.5. Designate a Specific Traffic Type for a Logical Network with the Manage Networks Window
6.3.6. Explanation of Settings in the Manage Networks Window
6.3.7. Network Labels

⁠6.3.1. Using the Networks Tab

The Networks resource tab provides a central location for users to perform network-related operations and search for networks based on each network's property or association with other resources.
All networks in the Red Hat Enterprise Virtualization environment display in the results list of the Networks tab. The New, Edit and Remove buttons allow you to create, change the properties of, and delete logical networks within data centers.
Click on each network name and use the Clusters, Hosts, Virtual Machines, Templates, and Permissions tabs in the details pane to perform functions including:
  • Attaching or detaching the networks to clusters and hosts
  • Removing network interfaces from virtual machines and templates
  • Adding and removing permissions for users to access and manage networks
These functions are also accessible through each individual resource tab.

⁠6.3.2. Creating a New Logical Network in a Data Center or Cluster

Summary
Create a logical network and define its use in a data center, or in clusters in a data center.
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Procedure 6.1. Creating a New Logical Network in a Data Center or Cluster

  1. Use the Data Centers or Clusters resource tabs, tree mode, or the search function to find and select a data center or cluster in the results list.
  2. Click the Logical Networks tab of the details pane to list the existing logical networks.
    • From the Data Centers details pane, click New to open the New Logical Network window.
    • From the Clusters details pane, click Add Network to open the New Logical Network window.
  4. Enter a Name, Description, and Comment for the logical network.
  5. Optionally select the Create on external provider check box. Select the External Provider from the drop-down list and provide the IP address of the Physical Network.
    If Create on external provider is selected, the Network Label, VM Network, and MTU options are disabled.
  6. Enter a new label or select an existing label for the logical network in the Network Label text field.
  7. Optionally enable Enable VLAN tagging.
  8. Optionally disable VM Network.
  9. Set the MTU value to Default (1500) or Custom.
  10. From the Cluster tab, select the clusters to which the network will be assigned. You can also specify whether the logical network will be a required network.
  11. If Create on external provider is selected, the Subnet tab will be visible. From the Subnet tab, select the Create subnet and enter a Name, CIDR, and Gateway address, and select an IP Version for the subnet that the logical network will provide. You can also add DNS servers as required.
  12. From the vNIC Profiles tab, add vNIC profiles to the logical network as required.
  13. Click OK.
Result
You have defined a logical network as a resource required by a cluster or clusters in the data center. If you entered a label for the logical network, it will be automatically added to all host network interfaces with that label.

Note

When creating a new logical network or making changes to an existing logical network that is used as a display network, any running virtual machines that use that network must be rebooted before the network becomes available or the changes are applied.

⁠6.3.3. Editing a Logical Network

Summary
Edit the settings of a logical network.
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Procedure 6.2. Editing a Logical Network

Important

A logical network cannot be edited or moved to another interface if it is not synchronized with the network configuration on the host. See Section 7.6.2, “Editing Host Network Interfaces and Assigning Logical Networks to Hosts” on how to synchronize your networks.
  1. Use the Data Centers resource tab, tree mode, or the search function to find and select the data center of the logical network in the results list.
  2. Click the Logical Networks tab in the details pane to list the logical networks in the data center.
  3. Select a logical network and click Edit to open the Edit Logical Network window.
  4. Edit the necessary settings.
  5. Click OK to save the changes.
Result
You have updated the settings of your logical network.

Note

Multi-host network configuration is available on data centers with 3.1-or-higher compatibility, and automatically applies updated network settings to all of the hosts within the data center to which the network is assigned. Changes can only be applied when virtual machines using the network are down. You cannot rename a logical network that is already configured on a host. You cannot disable the VM Network option while virtual machines or templates using that network are running.

⁠6.3.4. Explanation of Settings and Controls in the New Logical Network and Edit Logical Network Windows

⁠6.3.4.1. Logical Network General Settings Explained

The table below describes the settings for the General tab of the New Logical Network and Edit Logical Network window.
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Table 6.1. New Logical Network and Edit Logical Network Settings

Field Name
Description
Name
The name of the logical network. This text field has a 15-character limit and must be a unique name with any combination of uppercase and lowercase letters, numbers, hyphens, and underscores.
Description
The description of the logical network. This text field has a 40-character limit.
Comment
A field for adding plain text, human-readable comments regarding the logical network.
Create on external provider
Allows you to create the logical network to an OpenStack Networking instance that has been added to the Manager as an external provider.
External Provider - Allows you to select the external provider on which the logical network will be created.
Enable VLAN tagging
VLAN tagging is a security feature that gives all network traffic carried on the logical network a special characteristic. VLAN-tagged traffic cannot be read by interfaces that do not also have that characteristic. Use of VLANs on logical networks also allows a single network interface to be associated with multiple, differently VLAN-tagged logical networks. Enter a numeric value in the text entry field if VLAN tagging is enabled.
VM Network
Select this option if only virtual machines use this network. If the network is used for traffic that does not involve virtual machines, such as storage communications, do not select this check box.
MTU
Choose either Default, which sets the maximum transmission unit (MTU) to the value given in the parenthesis (), or Custom to set a custom MTU for the logical network. You can use this to match the MTU supported by your new logical network to the MTU supported by the hardware it interfaces with. Enter a numeric value in the text entry field if Custom is selected.
Network Label
Allows you to specify a new label for the network or select from existing labels already attached to host network interfaces. If you select an existing label, the logical network will be automatically assigned to all host network interfaces with that label.

⁠6.3.4.2. Logical Network Cluster Settings Explained

The table below describes the settings for the Cluster tab of the New Logical Network window.
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Table 6.2. New Logical Network Settings

Field Name
Description
Attach/Detach Network to/from Cluster(s)
Allows you to attach or detach the logical network from clusters in the data center and specify whether the logical network will be a required network for individual clusters.
Name - the name of the cluster to which the settings will apply. This value cannot be edited.
Attach All - Allows you to attach or detach the logical network to or from all clusters in the data center. Alternatively, select or clear the Attach check box next to the name of each cluster to attach or detach the logical network to or from a given cluster.
Required All - Allows you to specify whether the logical network is a required network on all clusters. Alternatively, select or clear the Required check box next to the name of each cluster to specify whether the logical network is a required network for a given cluster.

⁠6.3.4.3. Logical Network vNIC Profiles Settings Explained

The table below describes the settings for the vNIC Profiles tab of the New Logical Network window.
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Table 6.3. New Logical Network Settings

Field Name
Description
vNIC Profiles
Allows you to specify one or more vNIC profiles for the logical network. You can add or remove a vNIC profile to or from the logical network by clicking the plus or minus button next to the vNIC profile. The first field is for entering a name for the vNIC profile.
Public - Allows you to specify whether the profile is available to all users.
QoS - Allows you to specify a network quality of service (QoS) profile to the vNIC profile.

⁠6.3.5. Designate a Specific Traffic Type for a Logical Network with the Manage Networks Window

Summary
Specify the traffic type for the logical network to optimize the network traffic flow.
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Procedure 6.3. Specifying Traffic Types for Logical Networks

  1. Use the Clusters resource tab, tree mode, or the search function to find and select the cluster in the results list.
  2. Select the Logical Networks tab in the details pane to list the logical networks assigned to the cluster.
  3. Click Manage Networks to open the Manage Networks window.
    ⁠
    The Manage Networks window

    Figure 6.2. Manage Networks

  4. Select appropriate check boxes.
  5. Click OK to save the changes and close the window.
Result
You have optimized the network traffic flow by assigning a specific type of traffic to be carried on a specific logical network.

Note

Logical networks offered by external providers must be used as virtual machine networks; they cannot be assigned special cluster roles such as display or migration.

⁠6.3.6. Explanation of Settings in the Manage Networks Window

The table below describes the settings for the Manage Networks window.
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Table 6.4. Manage Networks Settings

Field
Description/Action
Assign
Assigns the logical network to all hosts in the cluster.
Required
A Network marked "required" must remain operational in order for the hosts associated with it to function properly. If a required network ceases to function, any hosts associated with it become non-operational.
VM Network
A logical network marked "VM Network" carries network traffic relevant to the virtual machine network.
Display Network
A logical network marked "Display Network" carries network traffic relevant to SPICE and to the virtual network controller.
Migration Network
A logical network marked "Migration Network" carries virtual machine and storage migration traffic.

⁠6.3.7. Network Labels

⁠6.3.7.1. Network Labels

Network labels can be used to greatly simplify several administrative tasks associated with creating and administering logical networks and associating those logical networks with physical host network interfaces and bonds.
A network label is a plain text, human readable label that can be attached to a logical network or a physical host network interface. There is no strict limit on the length of label, but you must use a combination of lowercase and uppercase letters, underscores and hyphens; no spaces or special characters are allowed.
Attaching a label to a logical network or physical host network interface creates an association with other logical networks or physical host network interfaces to which the same label has been attached, as follows:

Network Label Associations

  • When you attach a label to a logical network, that logical network will be automatically associated with any physical host network interfaces with the given label.
  • When you attach a label to a physical host network interface, any logical networks with the given label will be automatically associated with that physical host network interface.
  • Changing the label attached to a logical network or physical host network interface acts in the same way as removing a label and adding a new label. The association between related logical networks or physical host network interfaces is updated.

Network Labels and Clusters

  • When a labeled logical network is added to a cluster and there is a physical host network interface in that cluster with the same label, the logical network is automatically added to that physical host network interface.
  • When a labeled logical network is detached from a cluster and there is a physical host network interface in that cluster with the same label, the logical network is automatically detached from that physical host network interface.

Network Labels and Logical Networks With Roles

  • When a labeled logical network is assigned to act as a display network or migration network, that logical network is then configured on the physical host network interface using DHCP so that the logical network can be assigned an IP address.