On XenApp 6.0 or 6.5 servers, running on Windows 2008/R2, users might experience application launch issues when there are multiple NICs configured and enabled. Following error messages might be displayed:

“An error has occurred while connecting to the requested resource”

or

“An error occurred while making the requested connection”.

Workaround

To resolve the preceding issue, enable the XenApp policy for DNS address resolution, as shown in the following screen shot, either through the DSC or AD Group Policy. This results in the host servers FQDN being sent to the user’s ICA launch file, as opposed to an IP address.

Refer to the Knowledge Center article CTX128436 – How to Enable DNS Address Resolution in XenApp 6 for more information.

Note: This is a workaround to address these ICA connection issue on multi-home servers running 2008/R2. There is no current fix available. Additionally, there should be no other configuration changes required, except if the ICA connections are routed through a CAG portal. In this scenario, you need to enable DNS resolution on the Access Gateway.

Problem Cause

This issue usually occurs when the ICA listener configuration GUI is set to “All network adapters configured with this protocol” in the Network adapter tab, as shown in the following screen shot:

Note: If you use the ICA listener configuration GUI to manually change the “Network adapter” setting for the IP address configured for ICA traffic, you might see a similar application launch failure, but error messages might not be displayed. This can occur even if the command Netstat –a displays 1494 and 2598 as “listening”, and the ports are able to be accessed through telnet.

This configuration can result in the application launch ICA file containing the wrong IP address; the one that is not being used for ICA traffic. For example, in a PVS environment where one NIC is enabled with an IP address for PXE boot and another NIC is set with an IP address to handle the network traffic for ICA, the ica file might contain the PXE boot IP address causing the ICA application launch to fail.

CTX129131 – Hotfix XA600W2K8R2X64058 - For Citrix XenApp 6.0 for Windows Server 2008 R2 - English

CTX128436 – How to Enable DNS Address Resolution in XenApp 6

CTX130236 – Hotfix XA600W2K8R2X64077 - For Citrix XenApp 6.0 for Windows Server 2008 R2 - English