Notes from the lab: NetScaler VPX nsnet_connect prevents logon

When I started to rebuild my lab I came across the most strangest thing when configuring my NetScaler’s again. First a little background regarding my setup:

VMware ESXi 6.5u1 Hypervisors

NetScaler VPX 1000 Platinum Appliances

Distributed vSwitches with vlan trunks enabled

Dedicated NSVLAN for management (tagged)

Data transport vlan tagged


Whilst configuring and setting op the first and secondary nodes I’ve let the default appliance imports intact, that is 2vcpu and 2gb of ram and changed the E1000 nic’s to VMXNET3 and upgraded the VM compatibility format to the latest level. Nothing wrong here and started configuring both appliances with their NSIP’s respectively. Created the HA set and all was well.


Then it was time to put in the second nic which I’m going to use for my data transport with all vlan tagged interfaces and ip’s. Gave both appliances a shutdown and configured the nic’s accordingly (so it seemed at the time it was late 😊)


First node came back flawlessly but the second node wasn’t reachable anymore.. So put open the hypervisor console and I saw error messages regarding the nic and that the instance had crashed. When I would log in with the nsroot account I would get nsnet_connect prevents logon… Well ok.. that one was familiar to me with in mind the switch of E1000 and VMXNET3 devices (had this when upgrading a customer’s setup and that was the VM compatibility level, because you will need the latest build to be able to use VMXNET3, the default appliance level isn’t enough) but I’ve got both appliances up to date… I thought what the !%!@% and logged in with the nsrecover username to be able to login to the shell and dig in deeper. Thank god that worked and I was able to run the command ns_hw_err.bash which will check for any hardware error. And yes I instantly got the nic not present and reachable message. Looked at the configuration of the nic’s and a nice homer simpson moment the nic in question was still a E1000.. right… so turned it off and removed the nic, re-added it with the same MAC and presto all is well again.


Moral of the story double check your network settings when using VMXNET3!!!!

Notes from the field: XenDesktop RemotePC and Multi Licensing

Recently I got involved at a customer location which was going to use Remote PC catalogs in combination with their XenDesktop / XenApp 7.15 environment. This was no problem whatsoever to configure but on closer testing I encountered a bug that when you create for example a delivery group called “Windows 10 Remote PC” and adding more than one desktop the second, third and so on would get the published name of the local computer name e.g. WSDELL34951 which doesn’t comply with a standard name. The following can be observed for the delivery group name:Normally you would see at “PublishedName” an empty value, to correct this take a note of the “Uid” number and put in the following command:In this case my id was 4, and voila this will correct the name in StoreFront like in the following screenshot:

For the Multi Licensing part this needs to be done at the same level in powershell, see the following article:Multi-type licensing

In the previous screenshot you will see:

“LicenseModel” & “ProductCode” these need to be compliant with their respective edition of XenApp or XenDesktop license model, management is then per delivery group and not applicable for the entire site anymore. This would be a default for every new delivery group that will be created unless like in above screenshot you will add the “LicenseModel” & “ProductCode”


Hope this helps!

Notes from the lab: Windows Server 2016 black screen when launching any application

I came across an issue in my lab environment where the screen will go black while launching a session on Windows Server 2016. This is with XenApp/XenDesktop 7.15 LTSR
The following registry entry: DisableLogonUISuppression (D WORD Value 0) did not resolve the issue as stated in the following articles: and

Ultimatly after some trial and error the deletion of all subkeys from below registry entries resolved it:


Notes from the field: XenMobile Certificate Based Authentication lessons learned

Throughout the XenMobile deployments with Certificate Based Authentication(CBA) I came across some items which I thought was worth mentioning.

1. CBA up until Secure Mail 10.6.20 / Secure Hub 10.6.20 was requesting new certificates on SSL exceptions, in effect the exceptions were triggered on every SSL connection error that occurred and thus requesting a new certificate from the PKI, this got resolved in version 10.6.20 by not using Java codes anymore but instead reading the NetScaler Gateway error code which gets presented to the client.

2. The PKI / Credential Provider settings configured with template, validity, CRL and renewal configured on the PKI server won’t work for CBA, this is because CBA is not a payload certificate but only a SIGN method. WiFi certificate which get pushed do honor the validity, renewal and CRL options.

3. With above actions you’ve might get a really large PKI environment which is not necessary and therefore maybe you would need to migrate to a new PKI server, this can be done side by side by creating a new PKI/Credential Provider and configuring those accordingly and migrate in a controlled fashion

4. You might see issued Certificates which aren’t valid anymore or revoked and those devices still get access to the MAM store, this is resolved when you apply CRL mandatory or OCSP mandatory see the following article for some more information regarding CRL:

Hope these lessons learned help and if there are any comments or questions please feel free to drop them here.

Notes from the field: Be Proactive! Apple ATS is coming

For those who are not aware Apple has an upcoming change regarding App Transport Security (ATS)
The date it should be in effect was originally January 2017… but was pushed back for migration purposes, and the new date is yet a mystery.

It will have impact! Be proactive and check your XenMobile / NetScaler environments:

– NetScaler 11.1 will be the preferred build for TLS1.2 and the ECDHE cipher suites
– XenMobile 10.4 RP4 and XenMobile 10.5 have the TLS1.2 and ECDHE cipher suites (plus ATS hotfix)

Once ATS is enforced, Apple will require at least one cipher suite enabled from a specific list of cipher suites. Apple supported ATS cipher suites are:

If SSL-Offloading is used in combination with XenMobile, remember that 11.1 is the preferred build.

Notes from the field: NetScaler SDX LACP Flapping issue

I came across a peculiar issue regarding a new NetScaler SDX 14020 setup in combination with a Cisco Nexus C9372-PX-E and C9336PQ infrastructure, a new buildup of the SDX/VPX with multiple HA instances spinning and a working environment. LA sets configured for HA probes and everything nice and easy separated through vlan access. Long story short, at first it looked like a bug regarding the combination of NetScaler and Cisco: and created an support case with the follow ups with it, afterwards it seemed that the untagged management vlan setup was overlapping from data channels and the root cause for this was at the Cisco ACI side of things, the EPG(EndpointGroup) and BridgeDomain were overlapping in that case. The solution was to create a new and dedicated EPG/BridgeDomain for the data channels of the NetScaler.

So lessons learned:

  • Double check the setup of the ACI even if you get the “yes it’s correct” statement from your customer

Notes from the field: XenMobile Location services and SQL deadlocks

Came across a pretty specific issue in a large mobility environment regarding an old value from XenMobile 9 and still present in XenMobile 10, this is called device triangulation, with this the mobile service provider can triangulate the exact location from the device with constant updates regarding there location (this was an old value which was used with SMG and not applicable anymore).
This can cause significant impact on your database server with deadlocks.

The solution is to look for the following value:
Enable Device Triangulation
Preffered value: false
Default value: true

This won’t change application actions regarding geofencing because those are application and container specific.

Besides the above there is also an global value optional regarding location services in combination with iOS devices (the annoying popup you’ll get when enrolling the device which security people always ask you about 🙂 the following article will explain the values for XenMobile 9 and XenMobile 10:

Thanks to Arnaud Pain for going into more detail regarding location services client side, take a look at his blog:

Notes from the field: Provisioning Services 7.11/7.12 TLS 1.2 issue

Citrix Provisioning Servers can be showing a offline status because the SQL native client version (11.0.2100.60) installed with it will not support TLS 1.2 and due to this it will give an error in event viewer with event ID 11 – Undefined database error

Installing the latest version of SQL native client on the PVS servers should resolve the issue.

Notes from the field: Quick win: XenMobile remove bulk redeemed enrollments

When you are using enrollment invitations and you don’t clean this up for let’s say an environment with a few thousand of users/devices this could be a time absorbing action to do.
Luckily there is a quick win for this and you’ll want to create a query for “dbo.ENROLLMENT_PASS” on the Database server and remove those entries afterwards the redeemed invitations are gone.