Hi all,I'm having issues with a couple of Win7x64 Pro Toshiba R700 laptops at two separate sites losing connectivity to the 2008R2 DC's at each site. They'll work as per normal after startup and then all of sudden lose connectivity with the following symptoms. If the user has a file open, (Office 2010 and other apps) they'll be unable to save back to the network drive with error message "There has been a network or file permission error. The network connection may be lost. (file path)" Also, they are unable to access the other mapped network drives for that particular server with the error message "the specified network name is no longer available". Mapped drives to other 2003/2008R2 servers continue to function correctly. browsing to the inaccessible shares using the full domain name of the server (servername.domain.local) in Windows explorer succeeds. The laptops receive IP address and DNS settings via DHCP from the DC's in question. All other 100 or so XP/Win7 laptops/workstations are working correctly over 7 sites. We did have connectivity problems straight after upgrading the 2003 servers to 2008R2 and ended up disabling SMB2 on the servers and Win7x64 laptops/workstations which solved the initial problems for the majority of users but for some reason, these laptops are still having problems. It seems that the laptops will operate correctly until somehow something changes and possibly the domain suffix information changes or is lost for the one particular server that they're connected to. Due to the laptops being at a different site and the intermittent nature of the problem, it has been difficult to troubleshoot but this has been going on for weeks and one of the laptops belongs to a Managing Director so I need to get this sorted asap. Any help appreciated. cheers.

can you check the patch cable thats connected to the laptops ?. I feel the network gets disconnected at times and once it does you cannot access shared drives nor anyhting inside network.Regards, h9ck3r.

can you check the patch cable thats connected to the laptops ?. I feel the network gets disconnected at times and once it does you cannot access shared drives nor anyhting inside network.Regards, h9ck3r.

Hi, Please try to disable RSS and TCP Checksum Offload on the particular server to see if the issue could be resolved. 1. Disable the TCP Chimney by using the below commands in an elevated command prompt. • Netsh int tcp set global RSS=Disabled • Netsh int tcp set global chimney=Disabled • Netsh int tcp set global autotuninglevel=Disabled • Netsh int tcp set global congestionprovider=None • Netsh int tcp set global ecncapability=Disabled • Netsh int ip set global taskoffload=disabled • Netsh int tcp set global timestamps=Disabled 2. Disable any features related to offloading or Receive side scaling on the advanced configuration of the NIC's properties. 3. In Knowledge Base article 888750, please perform Methods 2 and 3. 888750 Slow performance when you try to access resources on your Virtual Server 2005 host computer from a guest virtual machine http://support.microsoft.com/default.aspx?scid=kb;EN-US;888750 4. Restart the server. Best Regards Scott Xie

ok, so far this issue seems to be solved as the user has reported no more issues. when running ipconfig, we noticed that there were multiple entries in the dns suffix (about 17 entries) relating to another companies domain. The user has Cisco vpn clients for the domain in question. Each dns suffix entry related to a virtual network adapter. Deleting all of the virtual adapters and removing all entries from the dns suffix dialog box seems to have fixed the issue. Bizaare but glad the problem has been fixed. cheers for your help.

seems i spoke too soon, problem is still occurring. I have tried disabling RSS and TCP offloading as in above post. Will let you know of any change.

seems i spoke too soon, problem is still occurring. I have tried disabling RSS and TCP offloading as in above post. Will let you know of any change.

Disabled RSS and TCP offloading but same problems still occurring.

Disabled RSS and TCP offloading but same problems still occurring.

Ok, the problem spread to 4 x HP Z200 Win7 64bit workstations and another laptop, same symptoms as above. The only similarity between the troublesome workstations is that they all have NVIDIA NVS 295 graphics cards. I had 3 other HP Z200's that had Quadro FX 1800 graphics cards that were working fine at the same site. I've updated the drivers to the performance drivers and the problem stopped immediately!! Not sure what's causing the initial problem but happy it's fixed. We have exactly the same setup at 5 other sites and no problems anywhere else. ???? This problem is solved for now.

Ok, the problem spread to 4 x HP Z200 Win7 64bit workstations and another laptop, same symptoms as above. The only similarity between the troublesome workstations is that they all have NVIDIA NVS 295 graphics cards. I had 3 other HP Z200's that had Quadro FX 1800 graphics cards that were working fine at the same site. I've updated the drivers to the performance drivers and the problem stopped immediately!! Not sure what's causing the initial problem but happy it's fixed. We have exactly the same setup at 5 other sites and no problems anywhere else. ???? This problem is solved for now.