I have a working 2 node Windows Cluster that runs SQL Server Always On Cluster. This cluster is sitting on 10.11.x.x subnet.
I need to get this cluster ready for possible DR scenario.
I need to add a new IP on different subnet – 10.14.y.y to thsi existing Windows custer. I will also need to add a new IP on 10.14.yy subnet to the existing AG Listener.
I used PowerShell to add a new IP Address cluster Resource to the cluster.
Add-ClusterResource –Name IPAddress141 –ResourceType “IP Address” –Group “Cluster Group”
But now I cannot change the subnet to 10.14.y.y to configure this new IP.
What am I missing? Do I need a second NIC configured to the new subnet? Is there even a way to add a second subnet to an existing cluster? Do I need to create a DR VM and add it to this cluster as a 3rd node?
Any help will be appreciated.

I tried to change the IP address on a new resource:

$res = Get-ClusterResource "IPAddress141" 
$param1 = New-Object Microsoft.FailoverClusters.PowerShell.ClusterParameter $res,Address,"10.14.y.y"
$param2 = New-Object Microsoft.FailoverClusters.PowerShell.ClusterParameter $res,SubnetMask,"255.255.252.0" 
$param3 = New-Object Microsoft.FailoverClusters.PowerShell.ClusterParameter $res,Subnet,"10.14.z.z/zz" 
$params = $param1,$param2,$param3
$params | Set-ClusterParameter

This doesn’t work. It gives me an error that it cannot save the new ClusterParameter.
Windows cluster GUI doesn’t work because it doesn’t see the new subnet.