The function gets the Office 365 IP address & URL information, in XML format, and returns the Product (O365, SPO, etc...), AddressType (IPV4,IPV6, OR URL), and Address (Ex: 13.107.6.152/31) information.

Get-O365IPAddress.ps1

Function Get-O365IPAddress
{
  <#
    .SYNOPSIS
    The function gets the Office 365 IP address & URL information.

    .DESCRIPTION
    The function gets the Office 365 IP address & URL information, in XML format, and returns the Product (O365, SPO, etc...), AddressType (IPV4,IPV6, OR URL), and Address (Ex: 13.107.6.152/31) information.

    .PARAMETER ErrorLog
    The file to log script errors to.  This parameter is not required.  Default file is C:\GetO365IPAddress-ErrorLog.txt.  In order for errors to be logged out to the file, the -LogErrors parameter must be used.

    Example Paramter Input:
    1. File name only     : Errors.txt    (Note: File is created in the current directory.)
    2. Using relative path: .\Errors.txt  (Note: File is created in the current directory.)
    3. Using full path    : C:\Errors.txt
    4. Using UNC path     : \\Server1\Errors\Errors.txt

    .PARAMETER LogErrors
    In order for script errors to be logged to the error file, this switch parameter must be used.  By default errors are not logged to the file.  This parameter is not required.

    .EXAMPLE
    Get-O365IPAddress
    .EXAMPLE
    Get-O365IPAddress -LogErrors -ErrorLog C:\GetO365IPAddress-ErrorLog.txt

    .INPUTS
    Office 365 IP address & URL information from https://support.content.office.net/en-us/static/O365IPAddresses.xml.

    .OUTPUTS
    Office 365 IP address & URL information, including Product (O365, EXO, SPO, etc...), AddressType (IPV4, IPV6, OR URL), and Address (Ex: 13.107.6.152/31).

    .NOTES
    Last Updated: 9/8/17

    .LINK
    Invoke-WebRequest
    https://support.office.com/en-us/article/Office-365-URLs-and-IP-address-ranges-8548a211-3fe7-47cb-abb1-355ea5aa88a2
    https://support.content.office.net/en-us/static/O365IPAddresses.xml
  #>

  [CmdletBinding()]
  Param
  (
    [Switch] $LogErrors,

    [ValidateNotNullOrEmpty()]
    [String] $ErrorLog = 'C:\GetO365IPAddress-ErrorLog.txt'
  )

  Try
  {
    Write-Verbose "Getting the Office 365 IP address & URL information from $O365IPAddresses."
    $O365IPAddresses = "https://support.content.office.net/en-us/static/O365IPAddresses.xml"
    [XML]$O365XMLData = Invoke-WebRequest -Uri $O365IPAddresses -DisableKeepAlive -ErrorAction Stop
    Write-Debug "Got the the Office 365 IP address information from $O365IPAddresses."
  } #End 'Try' block
  Catch
  {
    If($LogErrors)
    {
      Write-Verbose "Failed to get the Office 365 IP address & URL information from $O365IPAddresses.  See $ErrorLog for further information."
      $ErrorMsg = "$(Get-Date): [ERROR]: Failed to get the Office 365 IP address & URL information from $O365IPAddresses.  Error message was: $($_.Exception.Message)"
      $ErrorMsg | Out-File -FilePath $ErrorLog -Append
    } #End 'If' block
    Else
    {
      Write-Verbose "Failed to get the Office 365 IP address & URL information from $O365IPAddresses.  To log the error details, re-run Get-O365IPAddress with the -LogErrors parameter."
    } #End 'Else' block
  } #End 'Catch' block

  If($O365IPAddresses)
  {
    ForEach($Product in $O365XMLData.Products.Product)
    {
      ForEach($AddressList in $Product.AddressList)
      {
        $O365IPAddressProps = @{
                                 Product = $Product.Name;
                                 AddressType = $AddressList.Type;
                                 Addresses = $AddressList.Address
                               }
        $O365IPAddressObj = New-Object -TypeName PSObject -Property $O365IPAddressProps
        Write-Output $O365IPAddressObj
      } #End 'ForEach' block
    } #End 'ForEach' block
  } #End 'If' block
} #End 'Get-O365IPAddress' function