Retrieves a list of listening TCP and UDP ports along with their associated process names analogous to "netstat -anob"

Get-ListeningPorts.ps1

function Get-ListeningPorts {
    <#
    .SYNOPSIS
        Retrieves a list of listening TCP and UDP ports along with their associated process names.
    .DESCRIPTION
        This function fetches all listening TCP and UDP ports on the local machine and displays them along
        with the names of the processes that own those ports. An optional parameter allows filtering out IPv6 addresses.
    .PARAMETER NotIPv6
        If specified, the function will exclude IPv6 addresses from the results.
    .EXAMPLE
        Get-ListeningPorts -NotIPv6
    .NOTES
        Author:  Tim West
        Company: Air New Zealand
        Created: 2025-11-28
        Status: Production
        Version: 1.0
    #>
    [CmdletBinding()]
    param(
        [switch]$NotIPv6
    )

    $tcp = Get-NetTCPConnection -State Listen
    $udp = Get-NetUDPEndpoint

    $results = $tcp + $udp | ForEach-Object {
        $p = Get-Process -Id $_.OwningProcess -ErrorAction SilentlyContinue

        [PSCustomObject]@{
            Protocol     = if ($_ -is [Microsoft.Management.Infrastructure.CimInstance] -and $_.PSObject.TypeNames[0] -like "*TCP*") {"TCP"} else {"UDP"}
            LocalAddress = $_.LocalAddress
            LocalPort    = $_.LocalPort
            ProcessName  = $p.Name
        }
    }

    if ($NotIPv6) {
        $results | Where-Object { $_.LocalAddress -notlike ":" } | Sort-Object Protocol,LocalPort
    }
    else {
        $results | Sort-Object Protocol,LocalPort
    }
}