Create-OUIListFromWeb.ps1 optimization

[scriptingstudio]

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

[BornToBeRoot]

You can send me a pull request with the changes if you want. The lines below also need to be updated then.
This might be a bit faster, but how often do you generate/update the list?

I am not sure how to solve the problem with the duplicates. I currently use a set with key MAC value Vendor so i can directly access the key. If i use something like a list with for/foreach to match multiple vendors, this will get slow...

PowerShell_IPv4NetworkScanner/Scripts/IPv4NetworkScan.ps1

Lines 381 to 393 in ee650b3

	$OUIHashTable = @{ }
	Write-Verbose -Message "Read oui.txt and fill hash table..."
	foreach ($Line in Get-Content -Path $OUIListPath) {
	if (-not([String]::IsNullOrEmpty($Line))) {
	try {
	$HashTableData = $Line.Split('|')
	$OUIHashTable.Add($HashTableData[0], $HashTableData[1])
	}
	catch [System.ArgumentException] { } # Catch if mac is already added to hash table
	}
	}

[scriptingstudio]

A bit faster?
+= operator with strings in cycle of 100K lines takes a desparately HUGE amount of time.
Even this small optimization will speed up the script:

$Output = foreach($Line in $LatestOUIs -split '[\r\n]') {
    if($Line -match "base 16")
    {        
        # Line looks like: 2405F5     (base 16)		Integrated Device Technology (Malaysia) Sdn. Bhd.
        ($Line -replace '\s+', ' ').Replace(' (base 16) ', '|').Trim()
    }
}
$Output | Out-File -FilePath "$PSScriptRoot\Resources\oui.txt"

Also, in the scanner script try/catch with string evaluation in cycle of 30K lines is desparately slow.