User Error

ActiveSync woes–“Cannot get mail” and the case of the endless re-sync

Daniel — Fri, 03 Feb 2012 00:41:00 +0000

We recently experienced a really bizarre issue with our ActiveSync infrastructure. Users started complaining that their contacts were disappearing, and that their inboxes would re-synchronise constantly. All items in the inbox would disappear, and then reappear, starting with the oldest item. Some items were even dated at the Unix epoch. Users on iOS would get an error screen “Cannot get mail”, and downloading emails would time out or take a very long time.

We’re set up with TMG in our DMZ, which then sends traffic to a pair of CAS servers internally. We’ve been running Exchange 2010 SP2 and 2003 in co-existence for some time now, as some of our national offices are still in the process of migrating users across.

Our troubleshooting covered all areas, from looking at ActiveSync logs from IIS, running the Test-ExchangeConnectivity scripts, to testing on the devices themselves – you name it, we tried it. Here’s a quick way to turn up the logging level on ActiveSync using PowerShell:

Get-EventLogLevel | Where-Object {$_.Identity -like "MSExchange ActiveSync*"} | Set-EventLogLevel -Level High

The usual suggestions of permissions on the user account in AD and various other settings were not relevant. We even investigated the possibility that the problem could be caused by users still on iOS 4.0, which was known to cause issues and unusually high server load.

We then noticed that the TMG box would experience timeouts when requesting DNS resolution from our internal DNS servers. There were also errors from the TMG connectivity verifiers for AD that the LDAP servers were unreachable. This pointed to some sort of connectivity issue between TMG and and the CAS servers. Circumventing the TMG box by VPN’ing in or connecting via our corporate WiFi seemed to resolve the issue.

Upon inspection of our Netscreen 25 firewall, we noticed a lot of error messages about the source IP session limit being exceeded:

This is by design. It turned out that our DMZ had previously had IP based session limits set to a threshold of 128 sessions. This limit was being exceeded by the large number of ActiveSync users we now have. We bumped up that number to 512, and our problems are now resolved.

Funnily enough, while I was troubleshooting this issue, two ActiveSync troubleshooting-related articles appeared in my RSS reader of choice, Google Reader:

They’re both certainly worth reading, and are a great starting point if you’re experiencing ActiveSync issues.

Send a HTML email with PowerShell

Daniel — Tue, 31 Jan 2012 23:32:38 +0000

There’s a simple one-liner (expanded onto multiple lines for clarity) in PowerShell that allows you to send an email with HTML content derived from a HTML file: Send-MailMessage -Subject "Test email" -To "recipient@contoso.com" -From "me@contoso.com" -SmtpServer mail.contoso.com -BodyAsHtml (Get-Content "d:\templates\invite-template.htm" … Continue reading →

Adding style and Google Analytics to an Apache directory index (mod_autoindex)

Daniel — Sun, 15 Jan 2012 22:46:44 +0000

I recently had to spruce up a password-protected Apache directory index site that is being used to host some files for download.

In addition to making it look more presentable, I also discovered that you can inject code into the of the index page. This allowed me to achieve what I’d wanted to do for a while on that site – track visitors using Google Analytics.

To do so you already need to be using indexes and FancyIndexing. Then, simply add the following to your .htaccess file:

IndexHeadInsert ""

Here’s the rest of my .htaccess file, excluding the security section:

Options +Indexes

IndexOptions +FancyIndexing
IndexOptions +FoldersFirst
IndexOptions +XHTML
IndexOptions +HTMLTable
IndexOptions +SuppressRules
IndexOptions +NameWidth=*
IndexOptions +SuppressDescription

IndexIgnore .??* *~ *# HEADER* README* RCS CVS *,v *,t /resources /cgi-bin

IndexStyleSheet "/resources/style.css"

IndexHeadInsert ""

Native resolution not set after deploying via MDT 2010

Daniel — Fri, 06 Jan 2012 03:58:36 +0000

If your machines aren’t automatically having their display resolution set to their monitor’s native resolution after deployment via MDT, this may be the cause of the problem.

Although I’d previously deployed Vista and Windows 7 using MDT 2010, I’d never seen this problem. The issue occurred with a captured HP ProBook x86 Windows 7 Professional build.

I had to edit the unattend.xml for the task sequence in question, and delete the Display section from oobeSystem –> x86_Microsoft-Windows-Shell-Setup_neutral. Once this was done, the strange default of 1024 x 768 (where did that come from?) was no longer applied, and Windows Setup detected and set the maximum resolution.

MDT/WSIM fails to catalog a captured Windows 7 image

Daniel — Fri, 06 Jan 2012 03:29:30 +0000

Had an issue today where I was trying to catalog a captured Windows 7 WIM image, both through MDT 2010 and through WSIM directly.

Doing so comes up with an error:

Performing operation "generate" on Target "Catalog".
The operation failed to complete.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.ArgumentNullException: String reference not set to an instance of a String.
Parameter name: source
   at System.Globalization.CompareInfo.IsPrefix(String source, String prefix, CompareOptions options)
   at ?A0xfe36268f.ConvertToNtPath(String path)
   at Microsoft.ComponentStudio.ComponentPlatformInterface.CbsSessionAdaptor..ctor(String bootDrive, String imageWinDir, String servicingPath)
   at Microsoft.ComponentStudio.ComponentPlatformInterface.OfflineImageImpl.InitializePackages()
   at Microsoft.ComponentStudio.ComponentPlatformInterface.OfflineImageImpl..ctor(OfflineImageInfo imageInfo)
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle._InvokeConstructor(Object[] args, SignatureStruct& signature, IntPtr declaringType)
   at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
   at Microsoft.ComponentStudio.ComponentPlatformInterface.Cpi.PlatformImplementation.CreateOfflineImageInstance(OfflineImageInfo imageInfo)

The captured image I was trying to work with was of a 32-bit machine, and the WAIK tools I have installed on my desktop are the 64-bit ones.

The solution, as I learned here after a bit of searching, is to re-run the catalog operation on an x86 machine.

As you can’t install the 32-bit tools on a 64-bit machine, I installed the 32-bit tools on my laptop, fired up WSIM, opened the WIM image, re-ran the catalog operation, and it succeeded without errors.

You’d think that they could catch the exception and give you a useful message about running the catalog again on a compatible machine, but no…

PowerShell: Cancel all print jobs

Daniel — Thu, 17 Nov 2011 04:18:05 +0000

Here’s a quick PowerShell script I put together to delete all print jobs from our Windows Server 2008 R2 print server. It’s run overnight as a scheduled task. We do this because sometimes our print accounting software doesn’t clear out old jobs if users haven’t released them at the printer.

$printers = Get-WmiObject Win32_Printer

if ($printers.Count -eq 0) {
    Write-Host -ForegroundColor red "No Printers Found"
    exit
}

foreach ($printer in $printers) {

    if ($printer.Local -and $printer.Shared)
    {
        Write-Host -ForegroundColor Green "Cancelling all jobs on: $($printer.Name)"
        $printer.CancelAllJobs()

    }
}

It will only clear print jobs on local printers that are shared out. There’s some more info about the Win32_Printer class and the CancelAllJobs method on MSDN.

Note that I haven’t included any error-checking in this script at all, so run it manually first to see if it will work. As always, run at your own risk.

To schedule it, simply create a new scheduled task:

Run with highest privileges
Run whether user is logged on or not
Do not store password
Action: Start a program: C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
Arguments: -File “C:\path-to-script-file\name-of-script-file.ps1″

7-Zip tip – Quickly extract into a particular folder

Daniel — Thu, 20 Oct 2011 01:21:39 +0000

If you need to extract a file into a particular folder, what do you normally do? Some people may copy the Zip file into the destination folder, and then unzip it. Others may launch their unzip tool of choice’s file manager and use the unzip wizard to point to the destination folder.

7-Zip provides a handy way to do this. All you need to do is right-mouse-drag the Zip file to the destination folder, release the right-mouse button, and go to 7-Zip –> Extract … from within the context menu.

I’d been using 7-Zip for years before I figured this one out.

Tools of the trade, AKA tools I couldn’t do without: 7-Zip

Daniel — Thu, 20 Oct 2011 01:11:26 +0000

Another tool that I install straight away on new PCs is 7-Zip. I’m still amazed to see IT pros using unregistered (or dodgy) versions of WinRAR and WinZIP. 7-ZIP is better, faster, and free (open-source).

It can handle lots of formats, including ISO files, which I sometimes find handy.

7-Zip’s main features, as per their website. I’ve highlighted some of the formats that I regularly use 7-Zip with:

High compression ratio in 7z format with LZMA and LZMA2 compression
Supported formats:

Packing / unpacking: 7z, XZ, BZIP2, GZIP, TAR, ZIP and WIM
Unpacking only: ARJ, CAB, CHM, CPIO, CramFS, DEB, DMG, FAT, HFS, ISO, LZH, LZMA, MBR, MSI, NSIS, NTFS, RAR, RPM, SquashFS, UDF, VHD, WIM, XAR and Z.

For ZIP and GZIP formats, 7-Zip provides a compression ratio that is 2-10 % better than the ratio provided by PKZip and WinZip
Strong AES-256 encryption in 7z and ZIP formats
Self-extracting capability for 7z format
Integration with Windows Shell
Powerful File Manager
Powerful command line version
Plugin for FAR Manager
Localizations for 79 languages

Where: http://www.7-zip.org/
License: GNU LGPL – http://www.7-zip.org/license.txt