3.9. 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.
    Setting a label on a role network (for instance, "a migration network" or "a display network") causes a mass deployment of that network on all hosts. Such mass additions of networks are achieved through the use of DHCP. This method of mass deployment was chosen over a method of typing in static addresses, because of the unscalable nature of the task of typing in many static IP addresses.