Address         CIDR Description                               VLAN
-------         ---- -----------                               ----
10.15.10.0        24 DMZ                                       3000
10.15.11.0        24 Voice                                     3010
10.15.12.0        24 Wireless                                  3020
10.15.13.0        28 Management                                3030
...              ... ...                                        ...

$testCon = Test-Connection hostname -Count 1

$allSubnets | ForEach-Object {
  if((checkSubnet -addr1 ('{0}/{1}' -f $_.Address, $_.CIDR) -addr2 $testCon.IPV4Address.IPAddressToString).Condition -eq $true)
  {
    [pscustomobject]@{
      subnet = ('{0}/{1}' -f $_.Address, $_.CIDR)
      desc = $_.Description
    }
  }
}