Well what’dya know. This keeps cropping up its ugly little head. Since the advent of SP2 for Windows Server 2003, the Network Salability Pack (and TCP Chimney size, etc.) seems to be causing more and more ‘intermittent network problems’, for Windows Server, SBS and I’ve seen it with SQL as well.
Sure enough, Microsoft patch 948496 ‘disables’ this and is part of the critical patch set (yeesh, I thought it was learned through service pack 2 of Windows NT that introducing new features in a service pack was a bad idea, yet here we are again). You can download the patch here (with caution, see below re: MOSS).
http://support.microsoft.com/kb/936594
Lots of symptoms (but be cautious, there are several reports that this breaks MOSS 2007, although I’ve yet to personally verify/experience this):
– When you try to connect to the server by using a VPN connection, you receive the following error message: Error 800: Unable to establish connection.
– You cannot create a Remote Desktop Protocol (RDP) connection to the server.
– You cannot connect to shares on the server from a computer on the local area network.
– You cannot join a client computer to the domain.
– You cannot connect to Microsoft Exchange Server from a computer that is running Microsoft Outlook.
– You can only connect to Web sites that are hosted on the server or on the Internet by using a secure sockets layer (SSL) connection. In this scenario, you cannot connect to a Web site that does not use SSL encryption.
– You experience slow network performance.
– You cannot create an outgoing FTP connection from the server.
– The DHCP Server service crashes.
– Clients experience slow domain logons.
– Network Address Translation (NAT) clients that are located behind Windows SBS 2003 experience intermittent connection failures.
– You experience intermittent RPC communications failures.
– Clients that are configured as SecureNat clients may be unable to connect to the Internet.
– Some Outlook clients may be unable to connect to Exchange.
– You cannot run the Configure E-mail and Internet Connection Wizard successfully.
– Microsoft Internet Security and Acceleration (ISA) Server blocks RPC communications.
– Clients cannot visit the http://companyweb Web site.
– You cannot browse Internet Information Services (IIS) Virtual Directories.