Can you add the ability to scan multiple ports? Then this would be an all around best tool to use. thanks.

The current implementation is too slow and academic.
I would suggest to directly save as CSV. It looks more powershellish.

# "base" or "hex" can be chosen for filtering
# ";" or "," can be chosen as CSV delimiter
$progressPreference = 'silentlyContinue'
$LatestOUIs = (Invoke-WebRequest -Uri "https://standards-oui.ieee.org/oui/oui.txt" -UseBasicParsing).Content -split '[\r\n]' | 
Select-String '\(base 16\)' | 
. { process {$_ -replace '\s+\(base 16\)\s+',','}}
$progressPreference = 'Continue'

@('OUI,Name') + $LatestOUIs | Out-File -FilePath "$PSScriptRoot\Resources\oui.csv" -Encoding utf8

Yet there is a problem with duplicate ouis. The scanner selects the first entry which is likely incorrect.
CSV will eliminate dup issues.

UPDATE

duplicates
it is likely the same company with different names

Count Name   Group
----- ----   -----
    3 080030 {@{uoi=080030; name=NETWORK RESEARCH CORPORATION}, @{uoi=080030; name=ROYAL MELBOURNE INST OF TECH}, @{uoi=080030; name=CERN}}
    2 0001C8 {@{uoi=0001C8; name=THOMAS CONRAD CORP.}, @{uoi=0001C8; name=CONRAD CORP.}}

2nd
in PS7 Invoke-WebRequest is slow

MAC addresses and Vendors are incorrectly assigned if IPs start with same substring (e.g. 192.168.0.1 and 192.168.0.101).
Replace line 494 with
if($Line.TrimStart().StartsWith($IPv4Address.IPAddressToString + " "))
and $MAC of 192.168.0.1 will not get assigned again by 192.168.0.101.

Or use Get-NetNeighbor cmdlet to resolve MAC from IP (presumably slower for this implementation).

oui.txt is not being generated as the site is down. Here is a replacement I found on the web, however, it would require and update to your parser.

https://gist.githubusercontent.com/aallan/b4bb86db86079509e6159810ae9bd3e4/raw/846ae1b646ab0f4d646af9115e47365f4118e5f6/mac-vendor.txt

As soon as the script is saved in notepad++ using power shell extension, It gets disappeared/

Wenn die Start und End IP-Adresse gleich sind und Write-Process aufgerufen wird, wird in der Konsole ein Fehler ausgegeben das versucht wurde durch 0 zu teilen.

Der Scan funktioniert trotzdem!

Memory Leak when scanning. RunspacePool don't release resources properly.

Exception calling "EndInvoke" with "1" argument(s): "Exception of type 'System.OutOfMemoryException' was thrown." At C:\tools\ScanNetworkAsync.ps1:311 char:9 + $Jop_Results += $Job.Pipe.EndInvoke($Job.Result) + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorId : OutOfMemoryException

When I run the script, some IP are truncated like that : " 172.16.100... "

IP should be shown as 172.16.100.100

This occurs when I scan this range : 172.16.20.1 - 172.16.254.0 OR 172.16.99.1 - 172.16.101.1
But didn't occurs with this range : 172.16.99.99 - 172.16.101.1

I'm getting this error for Apple Airport Extreme Router.

Cannot index into a null array.
At
C:\Users\admin\Desktop\PowerShell_AsyncIPv4Scanner-master\PowerShell_AsyncIPv4Scanner-master\Scripts\New-IPv4Scan.ps1:399
char:17

• ... $Vendor = (($MAC_VendorList | Where-Object {$_.Assignment ...

•             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  

  • CategoryInfo : InvalidOperation: (:) [], RuntimeException
  • FullyQualifiedErrorId : NullArray

When using the "-EnableMACResolving" function, the above information was not detected. The IP and hostname were detected correctly, but nothing more.