Unable to launch Citrix XenDesktop 7.8 virtual desktop published through a NetScaler gateway

Problem

You completed deploying a new XenDesktop virtual desktop catalog, publishing it through a StoreFront, then providing access to the StoreFront through a NetScaler gateway:

Clicking on the desktop icon opens the window while the Delivery Controller attempts to launch and broker the session through the NetScaler to the Windows desktop:

The attempt eventually fails with the following error:

Desktop Viewer

The connection to “<VDI Desktop Group Name>” failed with status (1110).

Solution

While there this error could be caused by several configuration issues, one of the more common reasons I’ve come across is if the NetScaler appliance is configured with 2 networks where 1 is connected to an outside DMZ and the other is connected to an inside DMZ (or internal server network).  A common challenge with this type of setup is that the NetScaler’s default gateway is most likely going to be configured to go out to the internet (outside DMZ network) but this gateway usually does not allow the NetScaler to get back into the internal networks.  The error above is thrown because the NetScaler needs to communicate with the actual VDI but is unable to reach it through the internet gateway.  To get around this issue, either create a static route on the NetScaler to use the internal leg’s default gateway to reach the VDI subnet:

… or configure the gateway out through the internet to route traffic back to the internal network.