Database Reference
In-Depth Information
Table 8.3
Windows Failover Cluster Heartbeat Settings
The easiest way to modify the default cluster network settings to their recommended
values is to use Windows PowerShell. The following is an example of setting the
SameSubNetThreshold
to the recommended value of 10:
(Get-Cluster).SameSubnetThreshold=10
Tip
To ensure that a single NIC port or VLAN does not become a single point of
failure, it is recommended that you configure two virtual network adapters for the
cluster heartbeat, separate from the vNIC for application traffic. Each of the
heartbeat vNICs should be configured to use a different virtual switch port group,
VLAN, and physical NIC port.
Jumbo Frames
Standard Ethernet frames allow for a maximum transmission unit (MTU) of 1,500 bytes.
This means the maximum protocol data unit of a single packet that can be sent at one
time before fragmentation is needed is 1,500 bytes. Anything larger than 1,500 bytes
will need to be fragmented on the source, sent in multiple packets, and then reassembled
on the destination. Although this has been perfectly acceptable in the past with up to
1Gbps networks, it introduces overheads when transmitting large amounts of data and
on high-speed networks, such as 10Gbps and above.
