6.5.1

Table 1‑72. Networking Performance Enhancement Advice
# Resolution
1 Verify that VMware Tools is installed on each virtual machine.
2 If possible, use vmxnet3 NIC drivers, which are available with VMware Tools. They are optimized for high
performance.
3 If virtual machines running on the same host communicate with each other, connect them to the same vSwitch to
avoid transferring packets over the physical network.
4 Assign each physical NIC to a port group and a vSwitch.
5 Use separate physical NICs to handle the dierent trac streams, such as network packets generated by virtual
machines, iSCSI protocols, vMotion tasks.
6 Ensure that the physical NIC capacity is large enough to handle the network trac on that vSwitch. If the capacity
is not enough, consider using a high-bandwidth physical NIC (10 Gbps). Alternatively, consider moving some
virtual machines to a vSwitch with a lighter load or to a new vSwitch.
7 If packets are being dropped at the vSwitch port, increase the virtual network driver ring buers where applicable.
8 Verify that the reported speed and duplex seings for the physical NIC match the hardware expectations and that
the hardware is congured to run at its maximum capability. For example, verify that NICs with 1 Gbps are not
reset to 100 Mbps because they are connected to an older switch.
9 Verify that all NICs are running in full duplex mode. Hardware connectivity problems might result in a NIC
reseing itself to a lower speed or half duplex mode.
10 Use vNICs that are TCP Segmentation Ooad (TSO)-capable, and verify that TSO-Jumbo Frames are enabled
where possible.
Network Packets (Number)
The Network Packets chart displays the network bandwidth on a host.
This chart is located in the Home view of the Host Performance tab.
Table 1‑73. Data Counters
Chart Label Description
Packets Received Number of network packets received across the top ten physical NIC instances on
the host. The chart also displays the aggregated value for all NICs.
n
Counter: packetRx
n
Stats Type: Absolute
n
Unit: Number
n
Rollup Type: Summation
n
Collection Level: 3
Packets Transmied Number of network packets transmied across the top ten physical NIC instances on
the host. The chart also displays the aggregated value for all NICs.
n
Counter: packetTx
n
Stats Type: Absolute
n
Unit: Number
n
Rollup Type: Summation
n
Collection Level: 3
Chart Analysis
Network performance depends on the application workload and network conguration. Dropped network
packets indicate a boleneck in the network. To determine whether packets are being dropped, use esxtop
or the advanced performance charts to examine the droppedTx and droppedRx network counter values.
vSphere Monitoring and Performance
54 VMware, Inc.