I was asked to check the NIC settings on the 6 nodes in our Exchange 2007 mailbox cluster after one of the active nodes stopped communicating with the others. The servers are Windows 2003 x64 SP2 on identical hardware. I checked to confirm that the drivers were the same on all 12 Broadcom NICs and that they were the newest drivers. I confirmed that the KB948496 update was installed. I also confirmed in the Registry that EnableTCPChimney, EnableRSS and EnableTCPA were all set to 0, yet in the settings for each Network Adapter, Receive Side Scaling and TCP/IP Offload show as enabled. According to the article, you can use the above Registry settings to disable the above Network Adapter settings. Can someone tell me if I need to disable these settings on the Network Adapters, or can I just assume that the settings will be ignored because of the Registry settings?

Hi ChasBoston, Thanks for posting here. If you can confirm that these registry keys had been set to disabled and I think these features are disabled for adapters as well. The Microsoft Windows Server 2003 Scalable Networking Pack release http://support.microsoft.com/kb/912222 To figure out the root cause of this issue and narrow down it more effectually , could you discuss your cluster system and this connectivity issue in detail ? Have you recently modified any system settings for this server ? You may check if it would works with reset and reconfigure network settings on this server first. You may also start troubleshooting this issue with following KB325487: How to reset Internet Protocol (TCP/IP) http://support.microsoft.com/kb/299357 Advanced network adapter troubleshooting for Windows workstations http://support.microsoft.com/kb/325487 Thanks. Tiger Li TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.comPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Thanks for your reply. We actually had a support call to MS Product Support for this. The technician said that it looked like a network communications problem that was to blame, so he suggested we check the NIC settings on the problem server, which is why I had done that. We haven't had any issues since and we still don't really know why it happened. I will look into your suggestions, but I don't think there is much else I can do since the drivers are okay and as long as I can trust the Registry settings to disable the unwanted components. Cheers

Hi ChasBoston, If there is any update on this issue, please feel free to let us know. We are looking forward to your reply. Tiger Li TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.comPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.