Hi, I have a client who tried to install some apps on their SBS 2007 Server yesterday. One of them was IIS6. the other was business line tools. Since then their mail has been down. Transport service and Exchange wont start. Error logs: The Microsoft Exchange Transport service terminated unexpectedly. It has done this 1 time(s). The following corrective action will be taken in 5000 milliseconds: Restart the service. Process MSEXCHANGEADTOPOLOGYSERVICE.EXE (PID=2308). 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. The Directory Service Referral interface failed to service a client request. RFRI is returning the error code:[0x3f0]. Process MAD.EXE (PID=2444). 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. 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.ADSession.GetReadConnection(String preferredServer, ADObjectId& rootId) at Microsoft.Exchange.Data.Directory.ADSession.Find(ADObjectId rootId, String optionalBaseDN, ADObjectId readId, QueryScope scope, QueryFilter filter, SortBy sortBy, Int32 maxResults, IEnumerable`1 properties, CreateObjectDelegate objectCreator, CreateObjectsDelegate arrayCreator) at Microsoft.Exchange.Data.Directory.ADSession.Find(ADObjectId rootId, QueryScope scope, QueryFilter filter, SortBy sortBy, Int32 maxResults, IEnumerable`1 properties, CreateObjectDelegate objectCtor, CreateObjectsDelegate arrayCtor) at Microsoft.Exchange.Data.Directory.ADSession.Find[TResult](ADObjectId rootId, QueryScope scope, QueryFilter filter, SortBy sortBy, Int32 maxResults, IEnumerable`1 properties) at Microsoft.Exchange.Data.Directory.Recipient.ADRecipientSession.FindBySid(SecurityIdentifier sId) at Microsoft.Exchange.Autodiscover.Providers.Outlook.OutlookAutoDiscoverProvider..ctor(RequestData requestData) I dont really know where to start but this is quite urgent to only going to start my research now. Thanks

Ah, fixed. Had to Enable IPv6.

I'm not familiar with SBS 2007, but with SBS 2008 I believe the default web server is IIS 7. This sounds like what it was for your client as well and they decided to install IIS 6. If IIS is reinstalled on the same machine that Exchange 2007 is running on then exchange will also have to be reinstalled. I don't know if it might be possible to get around this if the machine was using IIS 7 and then IIS 6 was installed by uninstalling IIS 6. At first look it would appear the installation of IIS6 is the cause of the problem. Seehttp://support.microsoft.com/kb/320202for info on removing and reinstalling IIS on servers running exchange. Michael

That needs to be enabled as well. I ran into that problem after disabling IPv6 on one of our clients. Glad to hear you resolved this. Michael