Hi there, We have a Server 2008 R2 Standard tha have been working fine for a year. but somehow, about 2-3 weeks ago, it occasionally lost connection with DC. what was changed: - update backup exec to ver. 2010 R3 - update vRanger Backup & Replication to ver. 5 - update windows via windows update as usual This server only used for backup purposes and doesn't run any domain services. when it lost connection, it failed to: - access any network resources (e.g.: \\server\share) - can't open any web pages (whatever typed on the address bar, it returns with http:///) but strangely enough, it can still ping stuff fine. doing a restart will make it work again but this proved to be a temporary solution. there are 3 error messages that are frequently occurring (especially the NETLOGON and Group Policy errors): ------------------------------------ Log Name: System Source: Schannel Date: 20/05/2011 6:16:29 PM Event ID: 36870 Task Category: None Level: Error Keywords: User: SYSTEM Computer: host.domain.com Description: A fatal error occurred when attempting to access the SSL server credential private key. The error code returned from the cryptographic module is 0x8009030d. The internal error state is 10001. --> I don't know if this is related or a separate matter altogether, but I found this: http://www.zerohoursleep.com/2010/11/a-fatal-error-occurred-when-attempting-to-access-the-ssl-server-credential-private-key/ ------------------------------------ Log Name: System Source: Microsoft-Windows-GroupPolicy Date: 22/05/2011 4:03:58 PM Event ID: 1054 Task Category: None Level: Error Keywords: User: SYSTEM Computer: host.domain.com Description: The processing of Group Policy failed. Windows could not obtain the name of a domain controller. This could be caused by a name resolution failure. Verify your Domain Name System (DNS) is configured and working correctly. ------------------------------------ Log Name: System Source: NETLOGON Date: 22/05/2011 4:16:49 PM Event ID: 5719 Task Category: None Level: Error Keywords: Classic User: N/A Computer: host.domain.com Description: This computer was not able to set up a secure session with a domain controller in domain 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. ADDITIONAL INFO If this computer is a domain controller for the specified domain, it sets up the secure session to the primary domain controller emulator in the specified domain. Otherwise, this computer sets up the secure session to any domain controller in the specified domain. ------------------------------------ There's a post with similar issue to min: http://social.technet.microsoft.com/forums/en-us/exchangesvrgeneral/thread/73D8E61A-8EFB-4CBC-A158-96B74EEA8548 but unfortunately there's no detail on what the steps taken to fix this. I really appreciate any help on this!Andrew P.

Hello, this is a connectivity problem. Please use nslookup to check that you are able to solve DNS records correctly. Also, please make sure that you routes are well configured and that there is no firewall blocking traffic. This posting is provided "AS IS" with no warranties or guarantees , and confers no rights. Microsoft Student Partner Microsoft Certified Professional Microsoft Certified Systems Administrator: Security Microsoft Certified Systems Engineer: Security Microsoft Certified Technology Specialist: Windows Server 2008 Active Directory, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Network Infrastructure, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Applications Infrastructure, Configuration

thanks for the reply. the server is currently running fine (restarted this morning) so running nslookup returns with the correct server name/IP address. I will run this again when it encounter the issue. the routes (I assume the physical connections + IP config) are configured correctly. It has static IP and, again, has no changes for the last 6 months or so + working fine until 2-3 weeks ago. Windows firewall has been disabled. and there's no security software currently installed. more info: when the connectivity was lost, the network & sharing center didn't report anything. the "map" shows as having internet connection and can't the problem.Andrew P.

Please post ipconfig /all on all your DCs and the faulty server. This posting is provided "AS IS" with no warranties or guarantees , and confers no rights. Microsoft Student Partner Microsoft Certified Professional Microsoft Certified Systems Administrator: Security Microsoft Certified Systems Engineer: Security Microsoft Certified Technology Specialist: Windows Server 2008 Active Directory, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Network Infrastructure, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Applications Infrastructure, Configuration

Hi, If there is any update on this issue, please feel free to let us know. We are looking forward to your reply. BrentPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

apologies for the late reply. we're swamped with several issues this week. this server also has several issues (with some failed software/database connection) that might contribute to it so we're trying to fix the others first and see if this resolve the disconnection issues. I'll update this in a week.Andrew P.

yep. once we fixed the software thingy, everything went fine. still not sure why the software would cause those things but at least the errors haven't been occurring since 24th.Andrew P.