Information Technology Reference
In-Depth Information
network switch. With the uplink connected to the physical network, there is connectivity for
the VMkernel and the VMs connected to that vSwitch. But what happens when that physical
network adapter fails, when the cable connecting that uplink to the physical network fails, or the
upstream physical switch to which that uplink is connected fails? With a single uplink, network
connectivity to the entire vSwitch and all of its ports or port groups is lost. This is where NIC
teaming comes in.
NIC teaming involves connecting multiple physical network adapters to a single vSwitch.
NIC teaming provides redundancy and load balancing of network communications to the
VMkernel and VMs.
Figure 5.28 illustrates NIC teaming conceptually. Both of the vSwitches have two uplinks,
and each of the uplinks connects to a different physical switch. Note that NIC teaming sup-
ports all the different connection types, so it can be used with ESXi management networking,
VMkernel networking, and networking for VMs.
Figure 5.28
Virtual switches
with multiple
uplinks off er redun-
dancy and load
balancing.
ESXi host
ESXi mgmt
network
VLAN100 port
group
VLAN200 port
group
VMkernel port
vSwitch0
vSwitch1
Network
switch
Redundant
switch
Figure 5.29 shows what NIC teaming looks like from within the vSphere Web Client. In this
example, the vSwitch is coni gured with an association to multiple physical network adapters
(uplinks). As mentioned previously, the ESXi host can have a maximum of 32 uplinks; these
uplinks can be spread across multiple vSwitches or all tossed into a NIC team on one vSwitch.
Remember that you can connect a physical NIC to only one vSwitch at a time.
