[Also posted to microsoft.public.windows.server.sbs[ Running a mix of WinXP Pro and Vista Business clients on our LAN - Windows Small Business Server 2003 Premium-based. For unknown reasons, the Vista clients "lost" their network connection this morning. No IP, can't see the server in Network Places (althought they CAN see other computers). I can PING the localhost, but got error code 1231 for anthing else. A quick search saw it might be the TCP/IP stack or Winsock. Tried "netsh int ip reset", reboot, "netsh winsock reset", reboot, "netsh wi9nsock reset catalog", reboot, uninstall the network adapter, reboot ..... all with the same result on all Vista clients. I made a very minor GP change on the server yesterday, so I restored the GPO's from 2 weeks ago, that wasn't it. Did a restore on my PC to ~24 hours ago when all was well, that wasn't it. I've gone through the Event logs but I don't see anything jumping out at me. What's really odd is that WinXP clients are just fine; and I put static IP's on the Vista clients and they can get on the internet (although Network and Sharing Center shows a rex X between the server and the internet), see network assets, print. However, Exchange won't work ("Disconnected") and Windows Mail also is "Disconnected". What's going on, and how can I fix it? Many thanks in advance! Mike Mike Webb, IT Admin, Platte River Whooping Crane Maintenance Trust, Inc.

Hi Mike, Thank you for posting. Based on my research, I would like to suggest the following: 1. Check the DHCP server ================= May I know if the DHCP server is a Windows based server? If so, please ensure your DHCP server was Authorized in AD console. In Windows Server 2003, DHCP servers in an Active Directory-based domain must be authorized to prevent rogue DHCP servers from coming online. Any Windows Server 2003 DHCP Server that determines itself to be unauthorized will not manage clients. Authorize a DHCP server ---------------------------- 1) Click Start , click Programs , click Administrative Tools , and then click DHCP . NOTE : You must be logged on to the server with an account that is a member of the Enterprise Administrators group. 2) In the console tree of the DHCP snap-in, select the new DHCP server. If there is a red arrow in the lower-right corner of the server object, the server has not yet been authorized. 3) Right-click the server, and then click Authorize . 4) After a few moments, right-click the server again, and then click Refresh . There should be a green arrow in the lower-right corner to indicate that the server has been authorized. 2. Regarding the Red X, it can be caused by the factor that the Network Location Awareness service didnt work properly. Therefore, please check the services status on the problematic computers. The network connectivity status incorrectly appears as "Local only" on a Windows Server 2008-based or Windows Vista-based computer that has more than one network adapter http://support.microsoft.com/kb/947041 3. Just for a test, you can add a newly installed Windows Vista computer to the domainand check the results.If the issue persists, please help gathering the following information for further research: 1. Run ipconfig/all on the problematic computer and post the report to the thread. 2. Capture the network packet on the ==================== 1) Download NetMon3.2 from the following website and install it on the computer http://www.microsoft.com/downloads/details.aspx?FamilyID=f4db40af-1e08-4a21-a26b-ec2f4dc4190d&DisplayLang=en 2) Log onto the machines, right-click the Netmon icon and select Run as Administrator to launch NetMon3.2. 3) In the Microsoft Network Monitor 3.2 window, click Create a new capture tab 4) In the new tab, select all the Network Adapters in the Select Networks window. 5) After that, press F10 to start NetMon. 6) Try to re-produce the problem. 7) Go back to the NetMon window and press F11 to stop the NetMon. 3. May I know which changes have been made on the Group Policy settings. Please run the tool gpresult on the server and client sides to export the current Group Policy settings for our further research. Open an elevated command prompt, type the following command, and then press ENTER: gpresult /v >c:\ policy.txt 4. Please check the event log on both the server and client sides to check if there are any related errors. Please use Windows Live SkyDrive (http://www.skydrive.live.com/) to upload the file and share the URL with me. Thanks. Nicholas Li - MSFT