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8.2. Understanding the Default Behavior of Controller and Port Interfaces

When controlling teamed port interfaces using the NetworkManager daemon, and especially when fault finding, keep the following in mind:
  1. Starting the controller interface does not automatically start the port interfaces.
  2. Starting a port interface always starts the controller interface.
  3. Stopping the controller interface also stops the port interfaces.
  4. A controller without ports can start static IP connections.
  5. A controller without ports waits for ports when starting DHCP connections.
  6. A controller with a DHCP connection waiting for ports completes when a port with a carrier is added.
  7. A controller with a DHCP connection waiting for ports continues waiting when a port without a carrier is added.


The use of direct cable connections without network switches is not supported for teaming. The failover mechanisms described here will not work as expected without the presence of network switches. See the Red Hat Knowledgebase article Why is bonding not supported with direct connection using crossover cables? for more information.