Host Virtual Adapters and Types of Networks Needed in a
Hyper-V Host
A Hyper-V host needs many types of network connectivity, especially if it’s part of a
cluster. It’s critical that each type of traffic gets the required amount of bandwidth to
ensure smooth operation. Additionally, resiliency is likely required for many types of
connections to protect against a single network adapter failure. The following key
types of network connectivity are required for a Hyper-V host:
Management Communication to the host for management such as remote
desktop (RDP), WS-MAN for remote PowerShell and Server Manager, and basic
file copy operations. Sometimes backup operations will be performed over the
management network, or a separate backup network may be required.
VM Traffic related to virtual machines connected to a virtual switch
Live Migration The data related to moving a virtual machine between hosts, such
as the memory and even storage of a virtual machine
Cluster/CSV Cluster communications and Cluster Shared Volumes data
SMB 3 Windows 2012 makes SMB an option for accessing storage containing
virtual machines, which would require its own dedicated connection.
iSCSI If iSCSI is used, a separate network connection would be used.
Traditionally, to ensure the required guaranteed bandwidth for each type of network
communication, a separate network adapter was used for each type of traffic.
However, it is possible to combine the first four types of network with either of the
last two, but the use of separate network interfaces makes the implementation
potentially easier to manage. Look at the preceding list again. That is a lot of network
adapters—and that list is without resiliency, which may mean doubling that number,
which is typically not practical. This is also outlined in the Microsoft networking
guidelines at the following location:
http://technet.microsoft.com/en-us/library/ff 428137 (v=WS. 10 ).aspx
Your connectivity may look like Figure 3. 42. Not only does this require a lot of
network adapters, but there is a huge amount of wasted bandwidth. For example,
typically the Live Migration network would not be used unless a migration is
occurring, and normally the Cluster network has only heartbeat and some minimal
Metadata redirection for CSV, but the high bandwidth is needed for when a Live
Migration does occur or when a CSV goes into redirection mode. It would be better if
the network bandwidth could be used by other types of communication when the
bandwidth was available.