Information Technology Reference
In-Depth Information
Figure 5.44
With the use of
port groups and
VLANs in the
vSwitches, even
fewer vSwitches
and uplinks are
required.
ESXi host
vMotion port
(VLAN ID 50)
Test/dev port group
(VLAN ID 200)
Mgmt network
(VLAN ID 60)
IP storage port
(VLAN ID 70)
Production port group
(VLAN ID 100)
vSwitch0
VLAN
trunk
All VLANs
All VLANs
This time, you're able to provide NIC teaming to all the trafi c types involved—Management,
vMotion, IP storage, and VM trafi c—using only a single vSwitch with multiple uplinks.
Clearly, there is a tremendous amount of l exibility in how vSwitches, uplinks, and port groups
are assembled to create a virtual network capable of supporting your infrastructure. Even given
all this l exibility, though, there are limits. Table 5.1 lists some of the limits of ESXi networking.
Virtual Switch Configurations: Don't Go Too Big or Too Small
Although you can create a vSwitch with a maximum of 4088 ports (really 4096), it is not recom-
mended if you anticipate growth. Because ESXi hosts cannot have more than 4096 ports, if you
create a vSwitch with 4088 ports, then you are limited to a single vSwitch on that host. With only
a single vSwitch, you may not be able to connect to all the networks that you need. In the event you
do run out of ports on an ESXi host and need to create a new vSwitch, you can reduce the number
of ports on an existing vSwitch. h at change requires a reboot to take eff ect, but vMotion allows
you to move the VMs to a diff erent host to prevent VM downtime.
You also want to be sure that you account for scenarios such as a host failure, when VMs will be
restarted on other hosts using vSphere HA (described in more detail in Chapter 7, “Ensuring High
Availability and Business Continuity”). In this case, if you make your vSwitch too small (for example,
not enough ports), then you could run into an issue there also.
Our key takeaway: Virtual switch sizing is the factor of multiple variables that you need to consider,
so plan carefully! We recommend creating virtual switches with enough ports to cover existing
needs, projected growth, and failover capacity.
