Best Practices - Network - Building Hyper-V Infrastructure

Few best practices specific to Network Configurations to be considered while deploying a Hyper-V infrastructure. It may not be the full list, but this could be a base line.

1. Dedicated Network

Always consider dedicated network/VLAN for Hyper-V data, CSV, Live Migration and Management.

Hyper-V Data - The NIC which will be allocated with the Hyper-V Virtual Switch and will be used by the VMs to route network traffic. Priority should be give to have dedicated network interface for Hyper-V Data.

CSV - Its good to have a dedicated interface for CSV traffic. This will be really a life saver if one of the node loose the connectivity to the storage. I had an experience where all cluster nodes except one lost the connectivity to the storage and all the VMs on the problematic nodes where have CSV on IO Redirected mode which was in fact using my CSV Network. This could be an idle mostly, however its like a health insurance - very much valuable when the accident happens.

Live Migration - This will be used only while Live Migration happens. As we have more bandwidth, the live migration can complete more faster. In short, this network will be used to transfer the Virtual Machine memory and state.

Management - Obviously, Need to RDP or access the server through remoting which needs network connectivity.

2. Bios/Firmware/Drivers

It is also very critical to make sure that the server BIOS and Firmware is updated with the latest updates. As new OS version comes up, the manufacturers also provide the updates which will enable the server to make use of the new features.  The same applies to the drivers too. I had personally seen issues with my servers as the Firmware of NIC is not updated. So always better to keep all of them updated.

3. Jumbo Frames

For Live Migration networks, its recommended to enable Jumbo Frames. This should be done end to end - which means Jumbo Frames must be set on all the devices the packet routes to reach the destination. The value of Jumbo Frames depends on the manufacturer - however, you could go for the maximum value available on the NIC properties. To set this, Navigate to the properties of the Physical NIC -> Configure -> Advanced

Look for Jumbo Packet or Packet Size and see the maximum value from the drop down.

Test the end to end communication by using Ping -l "JumboFramesValue" -f
-f is to ensure no fragmentation. -l is for the size of the packet.

4. Binding Order

It is something which is very simple, but chance to miss out.

Ideally the binding should be as below order.

Management
LiveMigration
CSV
Hyper-V Data
iSCSI Adapter

5. DNS Registration

Disable DNS registration on all NICs except the management NIC.

6. IPV6

Disable IPv6 if its not used.

7. NIC Teaming

Recommended to have NIC Teaming, at-least for the Hyper-V data. If you are planning to use Teaming for Hyper-V Data, Please ensure the teaming mode and algorithm to be used based on the Host Operating System.

Windows Server 2012

Teaming Mode - Switch Independent
Load Balancing Mode - Hyper-V Port

Windows Server 2012 R2

Teaming Mode - Switch Independent
Load Balancing Mode - Dynamic

8. Configuring Preferred Network for CSV

Though we dedicate an interface, Please dont forget to make the respective configuration so that the dedicated network for CSV will be used as the preferred network for routing redirected IO.

Refer this Technet  articleon configuring preferred network for CSV.

9. Renaming the Cluster Network

Always good to rename the default Cluster Network names (Cluster Network 1/2/3/4 etc) to the appropriate name which is easy to relate. This can be done from Failover Cluster Manager -> Networks
Select a Network
Right click on the Cluster Network and take properties
Change the Name based on the subnet

10. Configuring Network for LiveMigration

Similarly, we need to configure the network to be used for LiveMigration if you have dedicated an interface for Live Migration. This can be easily done from Fail Over Cluster Manager.

Navigate to Failover Cluster Manager -> Networks
Right Click on Networks -> Live Migration Settings

Check the Networks to be used for Live Migration. You can have multiple networks and set priority so that if the network on first priority is down, the server will use the second network.

This step will be easy if the Cluster Networks are renamed according to the actual role.

11. Allow Cluster Communication on this network

On each Cluster Network, We need to define if the Network can be used for Cluster Network Communication. I would prefer to be enabled on Management, CSV and Live Migration networks.

12. Allow Clients to connect to this network

This should be enabled on the Management Cluster Network and must be disabled for Hyper-V Data Cluster Network.

13. Do not allow cluster communication on this network

Must be disabled on Hyper-V Data Cluster Network.

Again, this is not a definitive list, and always welcome any additional suggestions.