Dear all Thanks everyone for your replies. After restarting the domain controller last Friday the issues disappeared. I have a hunch that some MS security patches which were installed last Thursday might have broken something somewhere. However, I still have to test whether users would still be able to browse the web and access their network shares if the additional domain controller is shut down. Will be doing this later on this week. BTW all our clients are Windows 7.
Thanks Pierre From: [email protected] [mailto:[email protected]] On Behalf Of Ziots, Edward Sent: 05 July 2013 20:04 To: [email protected] Subject: RE: [NTSysADM] Unable to browse the Web when additional domain controller goes down Maybe a Pcap of the aforementioned traffic and I can review it, to assist?. Z Edward E. Ziots, CISSP, CISA, Security +, Network + Security Engineer Lifespan Organization [email protected]<mailto:[email protected]> Work:401-255-2497 This electronic message and any attachments may be privileged and confidential and protected from disclosure. If you are reading this message, but are not the intended recipient, nor an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that you are strictly prohibited from copying, printing, forwarding or otherwise disseminating this communication. If you have received this communication in error, please immediately notify the sender by replying to the message. Then, delete the message from your computer. Thank you. [Description: Description: Lifespan] From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Webster Sent: Friday, July 05, 2013 1:01 PM To: [email protected]<mailto:[email protected]> Subject: RE: [NTSysADM] Unable to browse the Web when additional domain controller goes down http://support.microsoft.com/kb/320760/en-us?p=1 The DNS Client Service does not revert to using the first server in the list in Windows XP Is this to what the which you are referring to in the afore mentioned DNS issue? Thanks Webster From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Jonathan Link Sent: Friday, July 05, 2013 11:56 AM To: [email protected]<mailto:[email protected]> Subject: Re: [NTSysADM] Unable to browse the Web when additional domain controller goes down Also related to this issue perhaps, might be the client OS? Wasn't XP really finicky about sticking to one DNS server, and if it went down, it didn't properly fail over to the secondary one? On Fri, Jul 5, 2013 at 11:46 AM, Andrew S. Baker <[email protected]<mailto:[email protected]>> wrote: Thanks, Pierre What DNS settings are configured on each of your DNS servers (in terms of their primary and secondary DNS lookups)? Regards, ASB http://XeeMe.com/AndrewBaker<http://xeeme.com/AndrewBaker> Providing Virtual CIO Services (IT Operations & Information Security) for the SMB market... On Fri, Jul 5, 2013 at 3:21 AM, Pierre-Marie Camilleri <[email protected]<mailto:[email protected]>> wrote: Hi Andrew Thanks for replying. Yes, all users were impacted. As far as I could see DNS replication seems to be working. However, when querying certain things I discovered some problems. I was able to resolve all sites from the additional DNS server but not from the primary DNS server. I next looked at the DNS manager and when looking at the primary DNS server I am seeing Automated Test Query Failed message. When checking the System Event Log of the primary domain controller I am seeing 5774 Events (NETLOGON) being logged every day. Regards Pierre From: [email protected]<mailto:[email protected]> [mailto:[email protected]<mailto:[email protected]>] On Behalf Of Andrew S. Baker Sent: 04 July 2013 18:47 To: ntsysadm Subject: Re: [NTSysADM] Unable to browse the Web when additional domain controller goes down Hi Pierre, Were all users impacted, or only some of them? How is external DNS handled? Forwarding Servers or Root Servers? Was DNS replication working properly prior to the shutdown? Can you resolve all the sites in question from the DNS server? Any eventlog messages? Regards, ASB http://XeeMe.com/AndrewBaker<http://xeeme.com/AndrewBaker> Providing Virtual CIO Services (IT Operations & Information Security) for the SMB market... On Thu, Jul 4, 2013 at 10:18 AM, Pierre-Marie Camilleri <[email protected]<mailto:[email protected]>> wrote: Hi everyone Had to shut down our additional domain controller due to maintenance work this afternoon and a few minutes later users complained that they were unable to browse the Web and also certain files from our file server. I cannot understand why this should have happened. Any idea why this happened? Thanks Pierre
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