6.0

Failback Policy
By default, a failback policy is enabled on a NIC team. If a failed physical NIC returns online, the virtual
switch sets the NIC back to active by replacing the standby NIC that took over its slot.
If the physical NIC that stands first in the failover order experiences intermittent failures, the failback policy
might lead to frequent changes in the NIC that is used. The physical switch sees frequent changes in MAC
addresses, and the physical switch port might not accept traffic immediately when an adapter becomes
online. To minimize such delays, you might consider changing the following settings on the physical switch:
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Disable Spanning Tree Protocol (STP) on physical NICs that are connected to ESXi hosts .
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For Cisco based networks, enable PortFast mode for access interfaces or PortfFast trunk mode for trunk
interfaces. This might save about 30 seconds during the initialization of the physical switch port.
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Disable the trunking negotiation.
Notify Switches Policy
By using the notify switches policy, you can determine how the ESXi host communicates failover events.
When a physical NIC connects to the virtual switch or when traffic is rerouted to a different physical NIC in
the team, the virtual switch sends notifications over the network to update the lookup tables on physical
switches. Notifying the physical switch offers lowest latency when a failover or a migration with vSphere
vMotion occurs.
Edit Failover and Load Balancing Policy for a vSphere Standard Switch
Use Load Balancing and Failover policies to determine how network traffic is distributed between adapters
and how to reroute traffic in the event of an adapter failure.
The Failover and Load Balancing policies include the following parameters:
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Load Balancing policy: The Load Balancing policy determines how outgoing traffic is distributed
among the network adapters assigned to a standard switch. Incoming traffic is controlled by the Load
Balancing policy on the physical switch.
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Failover Detection: Link Status/Beacon Probing
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Network Adapter Order (Active/Standby)
In some cases, you might lose standard switch connectivity when a failover or failback event occurs. This
causes the MAC addresses used by virtual machines associated with that standard switch to appear on a
different switch port than they previously did. To avoid this problem, put your physical switch in portfast
or portfast trunk mode.
Prerequisites
Launch the vSphere Client and log in to a vCenter Server system.
Procedure
1 Log in to the vSphere Client and select a host in the inventory pane.
2 Click the Configuration tab and click Networking.
3 Select a standard switch and click Properties.
4 Click the Ports tab.
5 To edit the Failover and Load Balancing values, select the standard switch item and click Edit.
vSphere Administration with the vSphere Client
260 VMware, Inc.