In Nutanix AHV networking, the default bond mode for a virtual switch is Active-Backup. In this mode, all traffic flows through a single active physical uplink, while other uplinks remain in standby mode to be used only in the event of a failure. This explains the observation that "only one of the physical NICs... is carrying VM traffic."

To utilize multiple physical uplinks simultaneously and balance the traffic, the administrator must change the bond mode to an Active-Active configuration. In AHV, this is achieved by configuring the bond mode to Balance-SLB (Source Load Balancing) or Balance-TCP (LACP). These modes distribute VM traffic across all available physical interfaces in the bond, thereby balancing the load.