I am facing RPC Server Unavailable issues in Win2k3 R2 sp2 Machines where Citrix Xenapp is installed. We had change in IP's in our DC,DNS and Member Servers in our Environment recently. Prior to that everything worked fine. Brief Environment Architecture : We have a firewall in place where Inside the firewall : Citrix , DB servers & App servers and outside the firewall : App servers The above servers are in different VLAN and Users are connecting from client machines are in separate VLAN. The servers which getting RPC server unavailable error is on servers which are inside the firewall. (There is no change in the environment only IP's range has been changed) The Servers are citrix boxes and they are accepting connections( 3-4 logins ) and later suddenly unable to RDP the boxes.After rebooting again they are accepting the connections. Error : The system cannot log you to the following error . THE RPC SERVER IS UNAVAILABLE. Below are the steps we have performed after IP change : * We have created Forward and Reverse Lookup Zones for servers. * We have registered DNS. ( ipconfig /registerdns) * Synced the time. (w32tm /resync ) * Checked all services. * Disjoined and rejoined the servers to domain. Below are the error messages in logs on citrix servers we are connecting : Systen Logs : EVENT ID : 5719 NETLOGON - This computer was not able to set up a secure session with a domain controller in domain ****** due to the following: The RPC server is unavailable. This may lead to authentication problems. Make sure that this computer is connected to the network. If the problem persists, please contact your domain administrator Application Logs : EVENT ID : 1219 - WINLOGON - Logon rejected for Domain\user1. Unable to obtain Terminal Server User Configuration. Error: The RPC server is unavailable. EVENT ID : 1053 - USERENV - Windows cannot determine the user or computer name. (The RPC server is unavailable. ). Group Policy processing aborted. Logon Error Message : Please help me on this issue. Chaitanya Varma MCTS

You would have continued the same old thread which had been created by you couple of weeks before. http://social.technet.microsoft.com/Forums/en-US/winservergen/thread/fa4b82a4-8f0a-430a-8e69-fd1e71847672/#fca21303-5d11-48bf-bb3d-ead6aa3fd97d Also, it would be a good idea to post this question in Citrix forums too. Don't be a prick ! Be reasonable and provide your feedback. Say something whether the suggestion was helpful or not, mark a reply as answer or click on to vote helpful if any suggestion really helps you, don't leave that choice to moderators, let the credit go to a contributor who has invested his precious time on your questions. Please be informed that, moderators are also humans and they also make mistakes ;-) Last but not the least, Unmark as answer if any post doesn't answer your question/s !!!