Over the past couple of years, I've noticed a growing trend - confusion around setting up networks on the failover cluster of a Hyper-V environment. It is important to implement a design that will balance traffic usage, set metrics, and ensure scalability for the future. Determining how this traffic flows is highly important, and should be a high priority in planning whether to have this traffic run through individually assigned NIC’s, vNIC’s, or carved converged network cards.

When we talk about balancing traffic usage, we are talking about creating multiple networks, so that all traffic is not running over the same network. From what I have seen in Hyper-V environments they are not aware of actually setting up multiple networks on the failover cluster side of Hyper-V. The concern seems to be only setting up the virtual networks on the hosts themselves. It is important to make sure our virtual networks are set up properly, but what about things like live migration, or cluster heartbeat. The last thing we want is all cluster traffic communicating over the same networks as our VMs.

Microsoft best practices on this, is to setup networks for the Heartbeat, data storage, management, and Live Migration. If you are using iScsi then you will also need a network for that (Osborne, 2013).

<strong>Hyper-V Failover Clustering Network Design</strong>

There are a few ways to design this, and will differ based on the size of an environment. What I do when setting up these different networks is:
<ol>
	<li>On each host, configure the IP’s on the network interface cards</li>
	<li>On each host, configure the virtual networks</li>
	<li>On the switch, I configure vlans to handle the different networks (you can also tag the vlan). These vlans include:</li>
</ol>
<blockquote>
<ul>
	<li>VM traffic – connected to the server vlan</li>
	<li>Heartbeat (CSV) – network used for communication between hosts, and cluster shared volumes</li>
	<li>Storage (if iSCSi) – network used for iSCSI storage. Do not allow cluster communication on this network.</li>
	<li>Live Migration – network used to Live Migrate VM’s to other hosts</li>
	<li>Management - network used to manage the hosts</li>
</ul>
</blockquote>
*VMtraffic will not show up in the failover cluster manager because it is not set to be managed in the virtual network settings of the host.

<strong>Configuring the Live Migration Network</strong>

Once the networks are setup, and the host nodes are added to the failover cluster, you will have to set what network you want to use for live migration, and then set the metrics using PowerShell.

Setting the Live Migration Network

Open the Failover cluster manager

Right-click networks

Select Live Migration settings

Check the box next to the Live Migration network

<strong>Setting Network Metrics</strong>

• Open PowerShell

• Type the following commands

• Import-module failoverclusters

• Get-cluster network - (shows networks)

• Get-cluster network “exampleLiveMigration”).Metric=”value”(900)

Example of auto metric settings:

Future blogs

Network Teaming in Hyper-V

Converged Network Cards, and carving them out