Updated version. OUI still not working well.

networkdiscovery2.ps1

@@ -183,24 +183,71 @@ function Get-DeviceCategory {
     }
 }
 
+# Function to get MAC vendor from MAC address using our database
+function Get-MacVendor {
+    param (
+        [string]$MacAddress
+    )
+    
+    # Clean the MAC address and get first 6 characters
+    $oui = ($MacAddress -replace '[-:\.]', '').Substring(0, 6).ToUpper()
+    
+    # Look up the manufacturer in our database
+    if ($ouiDatabase.ContainsKey($oui)) {
+        return $ouiDatabase[$oui]
+    }
+    return "Unknown"
+}
+
+# Function to categorize devices (kept same as previous version)
+function Get-DeviceCategory {
+    param (
+        [string]$Manufacturer,
+        [string]$DeviceName
+    )
+    # ... (previous categorization logic) ...
+}
+
 # Get local subnet information
 $localIP = (Get-NetIPAddress | Where-Object {$_.AddressFamily -eq 'IPv4' -and $_.PrefixOrigin -eq 'Dhcp'}).IPAddress
-$subnet = $localIP -replace '\.\d+$', '.0/24'
+$subnet = $localIP -replace '\.\d+$', ''
+
+# Fast parallel ping sweep to populate ARP cache
+Write-Host "Performing rapid ping sweep..." -ForegroundColor Yellow
+$pingJobs = 1..254 | ForEach-Object {
+    $ip = "$subnet.$_"
+    Start-Job -ScriptBlock {
+        param($ip)
+        Test-Connection -ComputerName $ip -Count 1 -ErrorAction SilentlyContinue
+    } -ArgumentList $ip
+}
+
+# Wait for all pings to complete
+Wait-Job $pingJobs | Out-Null
+Remove-Job $pingJobs
+
+# Short delay to ensure ARP cache is updated
+Start-Sleep -Seconds 2
+
+# Get ARP cache
+Write-Host "Retrieving network information..." -ForegroundColor Yellow
+$arpCache = Get-NetNeighbor | Where-Object {
+    $_.State -ne 'Unreachable' -and 
+    $_.LinkLayerAddress -ne '000000000000' -and 
+    $_.LinkLayerAddress -ne $null
+}
 
 # Initialize results array
 $deviceList = @()
 
-# Ping sweep the network
-1..254 | ForEach-Object {
-    $ip = $subnet -replace '0/24', $_
-    $ping = Test-Connection -ComputerName $ip -Count 1 -ErrorAction SilentlyContinue
-    
-    if ($ping) {
-        # Get ARP entry for the IP
-        $arpEntry = Get-NetNeighbor -IPAddress $ip -ErrorAction SilentlyContinue
+# Process each valid ARP entry
+foreach ($entry in $arpCache) {
+    if ($entry.LinkLayerAddress) {
+        $ip = $entry.IPAddress
+        $macAddress = $entry.LinkLayerAddress
         
-        if ($arpEntry -and $arpEntry.LinkLayerAddress -and $arpEntry.LinkLayerAddress -ne '000000000000') {
-            $macAddress = $arpEntry.LinkLayerAddress
+        # Only process if MAC address is valid (not zeros)
+        if ($macAddress -ne '000000000000') {
             $manufacturer = Get-MacVendor -MacAddress $macAddress
             $deviceName = try {
                 [System.Net.Dns]::GetHostEntry($ip).HostName
@@ -208,7 +255,6 @@ $deviceList = @()
                 "Unknown"
             }
             
-            # Only add devices with valid MAC addresses and known manufacturers
             $deviceList += [PSCustomObject]@{
                 IPAddress = $ip
                 DeviceName = $deviceName