Function Get-O365Endpoints
{
<# 
    .Synopsis 
    Powershell Method for pulling updated list of IP ranges for Office 365 endpoints from Microsoft's published xml file. Initial reference came from existing script on TechNet available here:
    https://gallery.technet.microsoft.com/Get-Office-365-IP-v4-562987d5
     
    .Description 
    Explanation: 
    https://support.office.com/en-us/article/Office-365-URLs-and-IP-address-ranges-8548a211-3fe7-47cb-abb1-355ea5aa88a2 
    XML file: 
    https://support.content.office.net/en-us/static/O365IPAddresses.xml 
  
    .Parameter Products 
    One or more Office 365 products by their abbreviation in the xml file: EOP, EXO, Identity, LYO, o365, OneNote, Planner,  
    ProPlus, RCA, SPO, Sway, WAC, Yammer.

    Note: Parameter will need to be maintained as products are added and removed by Microsoft, at which point the parameter 
    should be updated to match the current list of products in the xml file.
 
    .Parameter AddressType
    The desired information regarding the product: IPv4, IPv6, or URL.
        
    .Example 
    Get-O365EndPoints -Products LYO -AddressType IPv4

    .Example 
    Get-O365EndPoints -Products LYO -AddressType URL
 
    .Example 
    Get-O365EndPoints -Products LYO -AddressType IPv6 | Export-Csv Office365IPRanges.csv -NoTypeInformation 
#> 
[CmdletBinding()] 
Param 
( 
    [Parameter(Mandatory = $true)] 
    [ValidateSet("o365","LYO","Planner","Teams","ProPlus","OneNote","Yammer","EXO","Identity","Office365Video","WAC","SPO","RCA","Sway","EX-Fed","OfficeMobile","CRLs","OfficeiPad","EOP")] 
    [string[]]$Products = @(),
	
    [Parameter(Mandatory = $false)] 
    [ValidateSet("IPv4","IPv6","URL")] 
    [string[]]$AddressType = @()
) 

Begin{
	try { 
		$Office365IPsXml = New-Object System.Xml.XmlDocument 
		$Office365IPsXml.Load("https://support.content.office.net/en-us/static/O365IPAddresses.xml") 
    } 
	catch { 
		Write-Warning -Message "Failed to load xml file https://support.content.office.net/en-us/static/O365IPAddresses.xml" 
		break 
    } 
	if (-not ($Office365IPsXml.ChildNodes.NextSibling)) 
    { 
		Write-Warning -Message "Data from xml is either missing or not in the expected format." 
		break 
    } 
} 

Process{
    foreach ($Product in ($Office365IPsXml.products.product | Where-Object ({$Products -match $_.Name}) | Sort-Object Name)) 
            {If($AddressType -contains "IPv4")
                {
                    $IPv4Ranges = $Product | Select-Object -ExpandProperty Addresslist | Where-Object {$_.Type -match "IPv4"} 
                    $IPv4Ranges = $IPv4Ranges | Where-Object {$_.address -ne $null} | Select-Object -ExpandProperty address 
                    foreach ($Range in $IPv4Ranges) 
                    { 
                        $ProductIPv4Range = New-Object -TypeName psobject -Property @{ 
                            'Product'=$Product.Name; 
                            'IPv4Range'=$Range; 
                        } 
                        Write-Output $ProductIPv4Range | Select-Object Product, IPv4Range 
                    } 
                }
            ElseIf($AddressType -contains "IPv6")
                {
                    $IPv6Ranges = $Product | Select-Object -ExpandProperty Addresslist | Where-Object {$_.Type -match "IPv6"} 
                    $IPv6Ranges = $IPv6Ranges | Where-Object {$_.address -ne $null} | Select-Object -ExpandProperty address 
                    foreach ($Range in $IPv6Ranges) 
                    { 
                        $ProductIPv6Range = New-Object -TypeName psobject -Property @{ 
                            'Product'=$Product.Name; 
                            'IPv6Range'=$Range; 
                        } 
                        Write-Output $ProductIPv6Range | Select-Object Product, IPv6Range 
                    } 
                } 
            ElseIf($AddressType -contains "URL")
                { 
                    $URLRanges = $Product | Select-Object -ExpandProperty Addresslist | Where-Object {$_.Type -match "URL"} 
                    $URLRanges = $URLRanges | Where-Object {$_.address -ne $null} | Select-Object -ExpandProperty address 
                    foreach ($Range in $URLRanges) 
                    { 
                        $ProductURLRange = New-Object -TypeName psobject -Property @{ 
                            'Product'=$Product.Name; 
                            'URLRange'=$Range; 
                        } 
                        Write-Output $ProductURLRange | Select-Object Product, URLRange 
                    } 
                }
            Else
                { 
                    $AllRanges = $Product | Select-Object -ExpandProperty Addresslist 
                    $AllRanges = $AllRanges | Where-Object {$_.address -ne $null} | Select-Object -ExpandProperty address 
                    foreach ($Range in $AllRanges) 
                    { 
                        $AllProductRange = New-Object -TypeName psobject -Property @{ 
                            'Product'=$Product.Name; 
                            'Address'=$Range; 
                        } 
                        Write-Output $AllProductRange | Select-Object Product, Address
                    } 
                    
                }
        }
    }
}