Hi, Ive got an odd problem that starting happening last week. I have 2 web servers on one subnet in a remote location, and a local database server on another subnet. Every morning since last week, neither web server has been able to contact the database server. Ping requests from the web server to the DB server time out. Ping requests from the DB server to the web server time out on the first request, but then become successful for all the rest. Today I started a ping on the web server and watched it timeout repeatedly before hopping on the DB server and starting a ping there. Once requests were successful on the DB side, the web server could ping the DB. This has worked fine for well over a year, and to my knowledge nothing has changed. It seems to work fine the rest of the day once I do the ping to restore communication, but the next morning I have the same issue. Im not sure where to even begin looking into this, so any advice is appreciated. Thanks! DB server: Windows 2003 R2 Web server: Windows 2008 R2

Hi, Have you configure NIC teaming on servers? If so, please try to disable it. And also temporary disable TCP Offloading, RSS and TCP Chimney on web server, to see if the issue still persist. In addition, please upgrade the NIC driver on servers, and install the latest update on both servers. Information about the TCP Chimney Offload, Receive Side Scaling, and Network Direct Memory Access features in Windows Server 2008 http://support.microsoft.com/kb/951037 Best Regards, AidenAiden Cao TechNet Community Support

Hi, Have you configure NIC teaming on servers? If so, please try to disable it. And also temporary disable TCP Offloading, RSS and TCP Chimney on web server, to see if the issue still persist. In addition, please upgrade the NIC driver on servers, and install the latest update on both servers. Information about the TCP Chimney Offload, Receive Side Scaling, and Network Direct Memory Access features in Windows Server 2008 http://support.microsoft.com/kb/951037 Best Regards, AidenAiden Cao TechNet Community Support

Thanks for the ideas. NIC teaming is configured on the two of the servers, but since they're mission critical, I'm not going to be able to try disabling them (at this point anyway). I'll be updating the drivers and performing general updates soon, hopefully that resolves the issue. However, I believe the issue runs deeper... I've discovered this isn't limited to just the servers mentioned, but any machine on either subnet. Running a ping from the one direction resolves it for all the machines. In addition, I'm seeing a bunch of network errors on the DNS server. I'm still trying to go through them all and sort everything out. Therefore, I'll mark this as resolved.