6.5.1

Table Of Contents
Each virtual machine running on an ESXi host has an associated virtual port ID on the virtual switch. To
calculate an uplink for a virtual machine, the virtual switch uses the virtual machine port ID and the
number of uplinks in the NIC team. After the virtual switch selects an uplink for a virtual machine, it always
forwards traffic through the same uplink for this virtual machine as long as the machine runs on the same
port. The virtual switch calculates uplinks for virtual machines only once, unless uplinks are added or
removed from the NIC team.
The port ID of a virtual machine is fixed while the virtual machine runs on the same host. If you migrate,
power off, or delete the virtual machine, its port ID on the virtual switch becomes free. The virtual switch
stops sending traffic to this port, which reduces the overall traffic for its associated uplink. If a virtual
machine is powered on or migrated, it might appear on a different port and use the uplink, which is
associated with the new port.
Table 83. Considerations on Using Route Based on Originating Virtual Port
Considerations Description
Advantages
n
An even distribution of traffic if the number virtual NICs is
greater than the number of physical NICs in the team.
n
Low resource consumption, because in most cases the
virtual switch calculates uplinks for virtual machines only
once.
n
No changes on the physical switch are required.
Disadvantages
n
The virtual switch is not aware of the traffic load on the
uplinks and it does not load balance the traffic to uplinks that
are less used.
n
The bandwidth that is available to a virtual machine is
limited to the speed of the uplink that is associated with the
relevant port ID, unless the virtual machine has more than
one virtual NIC.
Route Based on Source MAC Hash
The virtual switch selects an uplink for a virtual machine based on the virtual machine MAC address. To
calculate an uplink for a virtual machine, the virtual switch uses the virtual machine MAC address and the
number of uplinks in the NIC team.
vSphere Networking
VMware, Inc. 100