The Virtual Desktop Agent registration fails with Event IDs 1221 and 1246.

Background

The following entries can be found in the event logs:

Event Type:     Warning
Event Source:     Citrix Desktop Service
Event Category:     None
Event ID:     1221
Date:          8/14/2009
Time:          8:11:14 AM
User:          N/A
Computer:          N/A
Description:
The Citrix Desktop Service cannot connect to the delivery controller ‘http://test.citrix.com:8080/Citrix/CdsController/IRegistrar' ‘IP Address’
Check that the system clock is in sync between this machine and the delivery controller. If this does not resolve the problem, please refer to Citrix Knowledge Base article CTX117248 for further information.

Event Type:     Warning
Event Source:     Citrix Desktop Service
Event Category:     None
Event ID:     1246
Date:          8/14/2009
Time:          8:11:14 AM
User:          N/A
Computer:          N/A
Description:
The Citrix Desktop Service has detected that the delivery controller test.citrix.com ‘IP Address’ cannot connect to the Service. One possible reason for this is that the 'Access this computer from the network' security policy does not allow the delivery controller server identity to access this machine.
Please check that a local or group policy is not set incorrectly to disallow access from the delivery controller servers.
VDA logging enabled reveals the following:

CdsEventWorkerAgentPolicyDisallowsController of type Warning with arguments: 'citrix.citrix.com' 'IP Address’.This is based on event log groups Registration http://test.citrix.com:8080/Citrix/CdsController/IRegistrar 12/08/10 00:00:00:
Failed to register withhttp://test.citrix.com:8080/Citrix/CdsController/IRegistrar
WCF Fault with detail CallbackCommunicationError, message 'Fail worker callback using SPN HOST/TestPC1.citrix.com and IP address ‘IP Address’
12/08/10 00:00:00: disposing server connection

Caution! Refer to the Disclaimer at the end of this article before using Registry Editor.

Add the DWORD “DisableTaskOffload” with a value of “1” and restart both the Virtual Desktop Agent and Desktop Delivery Controller.

Problem Cause

Checksum offload parameters may cause slow performance when enabled on the network adapter and Virtual Desktop Agent (VDA) may not register.
 

CTX121683 - Event ID 1221: The Citrix Desktop Service cannot Connect to the Delivery Controller