6.5.1

Table Of Contents
When you power on the virtual machine, the ESXi host selects a free virtual function from the physical
adapter and maps it to the SR-IOV passthrough adapter. The host validates all properties of the virtual
machine adapter and the underlying virtual function against the settings of the port group to which the
virtual machine belongs.
Networking Options for the Trac Related to an SR-IOV Enabled
Virtual Machine
In vSphere 5.5 and later, you can configure certain networking features on a virtual machine adapter that
is associated virtual function (VF). Use settings for the switch, for the port group, or for a port depending
on the type of the virtual switch (standard or distributed) that handles the traffic.
Table 102. Networking Options for a Virtual Machine Adapter That Uses a VF
Networking Option Description
MTU size Change the size of the MTU, for example, to enable jumbo
frames.
Security policy for VF traffic
n
If the guest operating system changes the initially set MAC
address of a virtual machine network adapter that uses a
VF, accept or drop incoming frames for the new address by
setting the MAC address changes option.
n
Enable global promiscuous mode for virtual machine
network adapters, including adapters that use VFs.
VLAN tagging mode Configure VLAN tagging in the standard or distributed switch,
that is, enable VLAN Switch Tagging (VST) mode, or let the
tagged traffic reach the virtual machines that are associated with
VFs, that is, enable Virtual Guest Tagging (VGT).
Using an SR-IOV Physical Adapter to Handle Virtual Machine
Trac
In vSphere 5.5 and later, both the physical function (PF) and virtual functions (VFs) of an SR-IOV capable
physical adapter can be configured to handle virtual machine traffic.
The PF of an SR-IOV physical adapter controls the VFs that virtual machines use, and can carry the
traffic flowing through the standard or distributed switch that handles the networking of these SR-IOV
enabled virtual machines.
The SR-IOV physical adapter works in different modes depending on whether it backs the traffic of the
switch.
Mixed Mode
The physical adapter provides virtual functions to virtual machines attached to the switch and directly
handles traffic from non SR-IOV virtual machines on the switch.
You can check whether an SR-IOV physical adapter is in mixed mode in the topology diagram of the
switch. An SR-IOV physical adapter in mixed mode appears with the icon in the list of physical
adapters for a standard switch or in the list of uplink group adapters for a distributed switch.
vSphere Networking
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