Hi all. Our Exchange server on a SBS2k8 std box is causing us a few headaches that we hope someone can help us getting it back together again. I've checked the error codes but they suggest that the network is down therefore unable to connect to the DC. We can access the server and it's resources over the network but cannot get Exchange to start therefore we're unable to retrieve our emails which is currently via the pop3 connector. As such OWA is also unaccessible. All was working fine until Saturday morning when we had trouble connecting Entourage to the Exchange. On looking at our logs we saw that Exchange Store/Transport/Pop3 etc was stopped and couldn't be re-started. We rebooted the server 3 times with same issues. The first error logs came in pretty much the same time we lost network activity that was resolved straight away and also the attempts of connecting 2x macs via Entourage to the Exchange. Here's the errors and if you need more info please let me know/ Many thanks in advance: The lastest 4 exceptions in the Apllication logs are as follows: Source: MSExchange Autodiscover/ Event ID: 1 / Task Catergory: Web Unhandled Exception "The Exchange Topology service on server localhost did not return a suitable domain controller." Stack Trace: at Microsoft.Exchange.Data.Directory.DSAccessTopologyProvider.GetConfigDCInfo(Boolean throwOnFailure) at Microsoft.Exchange.Data.Directory.TopologyProvider.PopulateConfigNamingContexts() at Microsoft.Exchange.Data.Directory.TopologyProvider.GetConfigurationNamingContext() at Microsoft.Exchange.Data.Directory.ADSession.GetConnection(String preferredServer, Boolean isWriteOperation, Boolean isNotifyOperation, ADObjectId& rootId) at Microsoft.Exchange.Data.Directory.ADGenericReader.GetNextResultCollection(Type controlType, DirectoryControl& responseControl) at Microsoft.Exchange.Data.Directory.ADPagedReader`1.GetNextResultCollection() at Microsoft.Exchange.Data.Directory.ADPagedReader`1.GetNextPage() at Microsoft.Exchange.Data.Directory.ADPagedReader`1.<GetEnumerator>d__0.MoveNext() at Microsoft.Exchange.Autodiscover.Providers.Outlook.OutlookAutoDiscoverProvider.SimpleConfigCache`2.Freshen(ADSystemConfigurationSession session) at Microsoft.Exchange.Autodiscover.Providers.Outlook.OutlookAutoDiscoverProvider.UpdateCacheCallback(Object stateInfo) Source: MSExchange ADAccess/ Event ID: 2501 / Task Catergory: General Process MSEXCHANGEADTOPOLOGY (PID=2036). The site monitor API was unable to verify the site name for this Exchange computer - Call=HrSearch Error code=80040a01. Make sure that Exchange server is correctly registered on the DNS server. Source: MSExchange ADAccess/ Event ID: 2114 / Task Catergory: Topology Process MAD.EXE (PID=1624). Topology discovery failed, error 0x80040a02 (DSC_E_NO_SUITABLE_CDC). Look up the Lightweight Directory Access Protocol (LDAP) error code specified in the event description. To do this, use Microsoft Knowledge Base article 218185, "Microsoft LDAP Error Codes." Use the information in that article to learn more about the cause and resolution to this error. Use the Ping or PathPing command-line tools to test network connectivity to local domain controllers. Source: MSExchange ADAccess/ Event ID: 2080 / Task Catergory: Topology Process MAD.EXE (PID=1624). Exchange Active Directory Provider has discovered the following servers with the following characteristics: (Server name | Roles | Enabled | Reachability | Synchronized | GC capable | PDC | SACL right | Critical Data | Netlogon | OS Version) In-site: SERVER31.mydomain.local CDG 1 0 0 1 0 0 0 0 0 Out-of-site:

Is the DNS service running and the server is correctly pointing at the DNS Server?Any help from:http://social.technet.microsoft.com/Forums/en-US/exchangesvrdeploy/thread/fa01db13-7a3a-46b4-991a-fecc07d12fa8?

Thanks Andy. That link re. IPv6 corrected the issue. Many thanks.