Friday, September 21, 2012

Launching a XenDesktop 5.6 desktop through a NetScaler Access Gateway throws the error: “Unable to launch your application. Contact your help desk with the following information: Cannot connect to the Citrix XenApp server. Protocol Driver error”

Problem

You attempt to launch a desktop in a XenDesktop 5.6 environment through a NetScaler Access Gateway but receive the following error message:

“Unable to launch your application. Contact your help desk with the following information: Cannot connect to the Citrix XenApp server. Protocol Driver error”

An example of some Checkpoint firewall logs logged between your web interface server and virtual desktops would be the following:

TCP packet out of state: unexpected post SYN packet - RST or SYN expected tcp_flags: ACK

Solution

Assuming that one of my previous posts about blocked session reliability and ICA ports does not apply to you:

Launching a XenDesktop 5.5 or 5.6 desktop through an NetScaler Access Gateway throws the error: “Unable to launch your application. Contact your help desk with the following information: Cannot connect to the Citrix XenApp server. Protocol Driver error”
http://terenceluk.blogspot.com/2012/04/launching-xendesktop-55-or-56-desktop.html

… then one of the other items to check is to ensure that your NetScaler Access Gateway actually has a static route to your virtual desktop’s subnet (assuming your NetScaler is set up with 2 networks).  The following route highlighted in yellow is the static route I had to enter so that the NetScaler knows how to get to the virtual desktop network:

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Wednesday, September 19, 2012

Logging onto Citrix NetScaler VPX 1000 access gateway throws the error: “You do not have permission to view this directory or page using the credentials that you supplied.”

Problem

You’ve just deployed a Citrix NetScaler VPX 1000 access gateway and you’re able to launch the gateway’s login page:

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You proceed to log into the page but receive the following error message:

401 – Unauthorized: Access is denied due to invalid credentials.

You do not have permission to view this directory or page using the credentials that you supplied.

Logging onto the Web Interface server and reviewing the event logs shows that event ID: 18001 errors are logged:

Site path: C:\inetpub\wwwroot\Citrix\XenAppExternal.

A communication error occurred while attempting to contact the Access Gateway authentication service at https://remote.someDomain.bm/CitrixAuthService/AuthService.asmx. Check that the authentication service is running. The message reported by the underlying platform was: The request failed with HTTP status 404: Not Found.. [Unique Log ID: eee32ba4]

For specific information about this message, see the Web Interface documentation at http://support.citrix.com/proddocs/topic/web-interface-impington/wi-log-messages-event-ids-hardwick.html.

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Solution

While there may be more than one reason that would cause this, the problem I came across was because my web interface did not have a host record configured to direct the:

remote.someDomain.bm

or the URL:

https://remote.someDomain.bm/CitrixAuthService/AuthService.asmx

… to the internal or external VIP of the NetScaler VPX appliance.  The reason why I say “internal” or “external” is because you have the choice of configuring the web interface server to call back to either virtual server’s IP depending on how you configured the access gateway.  I chose to unify the internal and external URL so when the web interface server attempts to access the URL, it may be connecting back to itself.

Creating a simple record in the host file:

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To point to the VPX appliance’s internal or external interface’s VIP that the virtual server is binded to corrected the problem.

Reconnecting a deleted mailbox in Exchange 2010

I’ve noticed that I keep coming across situations where I’ve been told to recover a deleted mailbox and I’ve repeatedly had to check my old notes to figure out how to do it because I don’t work with Exchange 2010 every day so this post serves to be a reference for myself a few months down the road when I don’t remember the PowerShell cmdlets.

Problem

You’ve accidentally disabled a user from within the Exchange Management Console as such:

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Solution

If the mailbox was deleted recently, you would need to use the following cmdlet to reveal the mailbox:

Clean-MailboxDatabase <database name>

Once you’ve ran the Clean-MailboxDatabase cmdlet, continue to list the mailboxes that you can reconnect with the following cmdlet:

Get-MailboxDatabase | Get-MailboxStatistics | where {$_.disconnectreason -ne $null} | ft displayname,database,disconnectreason -auto

An output similar to the following will be displayed:

DisplayName     Database DisconnectReason

-----------     -------- ----------------

Alicia Williams MailboxDB             Disabled

Susan Thompson  MailboxDB             Disabled

Proceed by executing the following cmdlet to reconnect the mailbox to the appropriate login:

Connect-Mailbox -Identity "Alicia Williams" -Database BRCL -User aliciaw

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Tuesday, September 18, 2012

NetScaler VPX Access Gateway NIC mappings in vSphere 5

The purpose of this post is more for something I can reference if I have to deal with a live NetScaler VPX appliance that’s in production and somehow need to identify the NIC mappings on the appliance to the vNICs in vSphere.  The following is the version:

Appliance:  NetScaler VPX
Version:  NS10.0: Build 70.7.nc, Date Sep 7 2012, 15:33:28

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By default, 2 NICs are configured on the NetScaler VPX appliance as shown here:

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The following are the interfaces and their vNIC mappings:

0/1 –> is mapped to –> Network adapter 1
1/1
–> is mapped to –> Network adapter 2

Here’s validation of the mappings through disconnecting the vNIC in VMware:

image image

Monday, September 17, 2012

Accessing a virtual desktop with Desktop Viewer in Citrix XenDesktop 5.6 briefly opens / flashes and closes

Problem

You’ve just deployed a new desktop catalog in Citrix XenDesktop 5.6 and attempt to access the desktop through the Web Interface server but the Desktop Viewer opens, flashes and then quickly closes:

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Reviewing the event logs in the application logs of the virtual desktops show that Event ID: 9032 is logged with the following description:

Citrix ICA could not configure Thinwire and switch to the remote ICA display. This error is typically caused by a prior RDP connection being made to the workstation. Rebooting the workstation or logging in at the
console will fix this.

Solution

I found quite a few older posts for earlier version of XenDesktop but later realized that this was caused by the fact that I had installed the VMware Tools after installing the XenDesktop VDA (Virtual Desktop Agent) which obviously was the wrong order.  Simply uninstalling and reinstalling the XenDesktop VDA Agent corrected the problem.