physically reside and will connect to the various services offered, such as line-of-
business (LOB) applications, file servers, domain controllers, and more.
Additionally, administrators may connect to certain management systems via
systems available on the corporate network, such as your VMM server. The VMM
environment needs to model the corporate environment so that virtual machines
can be given connectivity to the corporate environment to offer services.
Management Infrastructure servers typically are connected on a separate
management network that is not accessible to regular users and may not even be
routable from the corporate network.
Special Networks Certain types of servers require their own special types of
communications, such as those required for cluster communications, Live
Migrations, iSCSI, and SMB storage traffic. These networks are rarely routable and
may even be separate, isolated switches to ensure desired connectivity and low
latencies or they may use separate VLANs. Some organizations also leverage a
separate network for backup purposes.
Business Units/Tenants/Labs Separate networks may be required to isolate
different workloads, such as different business units, different tenants (if you are a
hoster), and lab/test environments. Isolation can be via various means, such as
VLANs, PVLANs, or network virtualization. These networks may require
connectivity out to the Internet, to other physical locations (common in hoster
scenarios where a client runs some services on the hoster infrastructure but needs
to communicate to the client’s own datacenter), or even to the corporate network,
which would be via some kind of gateway device. In Figure 3.13, Business Unit 2
requires connectivity out of its isolated network, while Business Unit 1 is
completely isolated with no connectivity outside of its own network.Each type of network would be modeled as a logical network in SCVMM. Additionally,
an organization may have different physical locations/datacenters, and SCVMM
allows you to define a logical network and include details of the sites where it exists
along with the configuration required at each site, known as a network site.
For example, suppose an organization has two locations, Dallas and Houston, and
consider just the management network in this example. In Dallas, the management
network uses the 10.1.1.0/24 subnet with VLAN 10, while in Houston, the
management network uses the 10.1.2.0/24 subnet with VLAN 20. This information
can be modeled in SCVMM by using network sites, which are linked to a SCVMM host
group and contained within a logical network. This enables SCVMM to assign not just
the correct IP address to virtual machines based on location and network but also the
correct VLAN/PVLAN. This is a key point. The logical network is modeling the
physical network, so it’s important that your objects match the physical topology, such
as correct IP and VLAN configuration.
Note that a network site in a logical network does not have to reflect an actual physical
location but rather a specific set of network configurations. For example, suppose that