Bug 2196469

Description of problem:In Rhel's implementation of this distro specific network file from hypervkvpd, "hv_set_ifconfig.sh", the parameter used by hyperv to set ipv6 netmask is not consumed IPV6NETMASK. This is handled well in other distros like Ubuntu but looks like all RHEL versions are missing this handling


Version-Release number of selected component (if applicable): All Rhel versions seem to have the problem


How reproducible:
Inject ipv6 to a hyperv rhel VM using powershell commands


Steps to Reproduce:
1. Create a rhel (any version, we tried 7.8) VM on hyperv setup
2. Inject IPv6 address statically in the VM using powershell tools.
 sample script:
Function Set-VMNetworkConfigurationDualIP{
[CmdletBinding()]
Param (
   [Parameter(Mandatory=$true,
              Position=0,
              ParameterSetName='Static',
              ValueFromPipeline=$true)]
   [Microsoft.HyperV.PowerShell.VMNetworkAdapter]$NetworkAdapter,

    [Parameter(Mandatory=$false,
              Position=0,
              ParameterSetName='Static')]
   [Switch]$IPV4V6
)

$VM = Get-WmiObject -Namespace 'root\virtualization\v2' -Class 'Msvm_ComputerSystem' | Where-Object { $_.ElementName -eq $NetworkAdapter.VMName } 
$VMSettings = $vm.GetRelated('Msvm_VirtualSystemSettingData') | Where-Object { $_.VirtualSystemType -eq 'Microsoft:Hyper-V:System:Realized' }    

$VMNetAdapters = $VMSettings.GetRelated('Msvm_SyntheticEthernetPortSettingData') 

$NetworkSettings = @()
foreach ($NetAdapter in $VMNetAdapters) {
   if ($NetAdapter.Address -eq $NetworkAdapter.MacAddress) {
       $NetworkSettings = $NetworkSettings + $NetAdapter.GetRelated("Msvm_GuestNetworkAdapterConfiguration")
   }
}



if ($IPV4V6) {
   $NetworkSettings[0].IPAddresses = @("192.168.1.106";"1234:1234:1234:1234::119")    
    $NetworkSettings[0].Subnets = @("255.255.255.0";"120")
   $NetworkSettings[0].DefaultGateways = @("192.168.1.1";"1234:1234:1234:1234::1")
   $NetworkSettings[0].DNSServers = @("192.168.1.8")
   $NetworkSettings[0].ProtocolIFType=4098
   $NetworkSettings[0].DHCPEnabled = $false
} else {
   $NetworkSettings[0].IPAddresses = @("192.168.1.109")
   $NetworkSettings[0].Subnets = @("255.255.255.0")
   $NetworkSettings[0].DefaultGateways = @("192.168.1.1")
   $NetworkSettings[0].DNSServers = @("192.168.1.10")
   $NetworkSettings[0].ProtocolIFType=4096
   $NetworkSettings[0].DHCPEnabled = $false
}


$Service = Get-WmiObject -Class "Msvm_VirtualSystemManagementService" -Namespace "root\virtualization\v2"
$setIP = $Service.SetGuestNetworkAdapterConfiguration($VM, $NetworkSettings[0].GetText(1))


if ($setip.ReturnValue -eq 4096) {
   $job=[WMI]$setip.job 

    while ($job.JobState -eq 3 -or $job.JobState -eq 4) {
       start-sleep 1
       $job=[WMI]$setip.job
   }
   write-host "**jobstate = $job.JobState "
   if ($job.JobState -eq 7) {
       write-host "Success"
   }
   else {
       $job.GetError()
   }
} elseif($setip.ReturnValue -eq 0) {
   Write-Host "Success"
}

} 


Actual results: IPv6 subnet mask still set to 64 in VM


Expected results:Ipv6 subnet mask should have been set to 120 as mentioned in steps of reproduction


Additional info: