Use the difference between event log time stamps to decide if you need to take action

Today I am on a long flight back to Indianapolis after a week of training at Microsoft. Being the geek that I am I decided to take a quick look at PowerShell.org to see if anybody in the community was having issues that I could help with before we took off. One community member needed to be able to tell if two events were being recorded more than 2 hours apart. If so, she wanted an action to take place.

I used the Subtract Method of the System.DateTime object that is given to you in the TimeCreated property of an individual event log to resolve this. In the below function, I have it extract the first two events that match the criteria in $EventHash. I then take the first returned event and subtract the second events time from the first and then look for the TotalHours property. If it is greater than the number of hours specified when the function was called, it returns True. If not, it returns False. It also has a built in safety. If 1 or less events are returned, the function defaults to False.

Function Get-EventTimeSpan
{
Param (
    [Parameter(Mandatory=$True)]$Hours
)
    # Specify the criteria for your event here.
    $EventHash = @{LogName = "System"; ID = 1014}

    # Recover the first two events from the event log that matches
    # the criteria in the $EventHash data.
    $EventData = Get-WinEvent -FilterHashtable $EventHash -MaxEvents 2

    # Verify that at least two events were recovered from the log.
    # If there are less than 2 events recovered, Execute the ELSE
    # Statement.  The Else statement should execute code if only one
    # or less events are found.
    If ($EventData.Count -eq 2)
    {
        If ((($EventData[0].TimeCreated).Subtract(($EventData[1].TimeCreated)).TotalHours) -lt $Hours)
        {
            # Return $False if the time between events is less than the
            # number of hours specified in $Hours.
            Write-Output $False
        }
        Else
        {
            # Return $False if the time between events is greater than the
            # number of hours specified in $Hours.
            Write-Output $True
        }
    } # End: If ($EventData.Count -lt 2)
      Else
    {
        #If there are less than 2 events in the event log, return $False
        Write-Output $False
    } # End: Else Statement for If ($EventData.Count -lt 2)
 


} # ---- End Function Get-EventTimeSpan ---------------------------------------

Comments

With the AD Recycle Bin Turned on, What Happens when you Create a User Account with a Password that does not meet the Password Policy?

This was an interesting observation from one of my Windows Server 2012 classes. While working with the AD Recycle bin in a lab, one of my students discovered some interesting accounts that were created. When he created user accounts that did not meet password complexity requirements, an account is temporarily made and then deleted. When a new password is provided that meets the password requirements, then a new account is made. We discovered this in two places. First off in the Active Directory Administrative Center. This is what caused the initial confusion. Take a look. This is in the Deleted Objects OU. You can see multiple deleted accounts for Test2 and one for Test3. Test3 is a valid, functioning user account. Using the PowerShell command Get-ADObject –IncludeDeletedObjects –Filter * –Properties ObjectSID we can see that indeed, two accounts were created, with one of them deleted. Notice the RID portion of the SID is different. ...

Sticky Key problem between Windows Server 2012 and LogMeIn

This week I instructed my first class using Windows Server 2012 accessed via LogMeIn and discovered a Sticky Key problem every time you press the Shift key. Here is my solution to resolve this. First off, in the Preferences of LogMeIn for the connection to the Windows Server, click General . Change the Keyboard and mouse priority to Host side user and click Apply at the bottom. On the Windows 2012 server, open the Control Panel – Ease of Access – Change how your keyboard works . Uncheck Turn on Sticky Keys . Click Set up Sticky Keys . Uncheck Turn on Sticky Keys when SHIFT is pressed five times . Click OK twice. If you are using Windows Server 2012 as a Hyper-V host, you will need to redo the Easy of Use settings on each guest operating system in order to avoid the Sticky Key Problem. Updated Information: March 20, 2013 If you continue to have problems, Uncheck Turn on Filter Keys .

Backup and Restore AD LDS with DSDBUTIL.exe

Active Directory Lightweight Directory Services allow you to create a directory service that allows applications to have access to user accounts, groups, and authentication similar to Active Directory Domain Services. The big advantage here is that the schema of the directory service will not be bound by the rules of an Active Directory database. Exchange 2007/2010, for example, use an instance of AD LDS on the Edge Transport Server to provide for user authentication from the internet. Because your Active Directory database is not exposed to the internet, this is more secure. Applications will handle most of the dirty work should they require AD LDS. You may want to make sure the database is being backed up and also have a restore plan in place. Should the database become corrupt, the application that uses that database will fail. This document will walk you through backing up and restoring an instance of AD LDS using the dsdbutil.exe command. Fi...

Jason Yoder, MCT

Search This Blog