ISA Server and Windows Server 2003 Service Pack 2
The ISA Server product team blog ISA Server and Windows Server 2003 Service Pack 2 states that it might be necessary to disable receive-side scaling (RSS) when running an ISA server on Windows 2003 SP2. In fact, according to Jim Harrison it is absolutely recommended to disable receive-side scaling *and* offload support in the TCP/IP stack. How to accomplish that is explained in the Microsoft KB article You may experience network-related problems after you install Windows Server 2003 SP2 or the Scalable Networking Pack.
However, depending on the NIC driver it might be necessary to disable also offloading of tasks to the NIC (DisableTaskOffload) as well as the TCP Chimney offload in the stack (EnableTCPChimney). This registry entries are found under the registry subkey HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters :
- DisableTaskOffload
Type: REG_DWORD
Values: 0, 1
- EnableTCPChimney
Type: REG_DWORD
Values: 0, 1
Update March 11, 2008: check out http://support.microsoft.com/kb/948496. This disables the “Scalable Network Pack” that has caused so much hate & discontent for ISA administrators the world over. So, add this to your “must include” for any ISA or RRAS deployment that includes Windows Server 2003 SP2.
HTH,
Stefaan
abhinaw Says:
August 17th, 2007 at 4:52 pm
We are having a clinet using Win 2003 Server SP2. Their network card is BroadCom NetXtreem gigabit nic, driver version is 7.100.0.0.
They started receiving ystem hang after applying SP2, we asked them to apply a patch published by microsoft on Aug 6, 2007(http://support.microsoft.com/kb/936594).
Problem still exists.
is it because of the Network adapter driver being old and not supporting the Offload.
We changed the REg files as follows and did not get any issues inhouse but VPN conenctivity is lost.
“EnableRSS”=dword:00000000
“EnableTCPA”=dword:00000000
“EnableTCPChimney”=dword:00000000
“DisableTaskOffload”=dword:00000001
any help is apprecieated.
thanks
-abhinaw
ISA Server and Windows Server 2003 Service Pack 2 - http://blogs.isaserver.org/pouseele/feed/ Says:
October 24th, 2007 at 5:07 pm
[…] ISA Server and Windows Server 2003 Service Pack 2 The ISA Server product team blog ISA Server and Windows Server 2003 Service Pack 2 states that it might be necessary to disable receive-side scaling (RSS) when running an ISA server on Windows 2003 SP2. In fact, according to Jim Harrison it is absolutely Read More… […]
markwilson.it » Problems with Hyper-V, ISA Server 2006 and TCP offloading Says:
March 7th, 2008 at 8:03 pm
[…] Even after this change, I still couldn’t successfully ping resources on the external side of the ISA Server from the private network, but I was sure I was onto something. I stopped looking for problems with ISA Server and DNS, and instead I focused my efforts on TCP Offload issues with Hyper-V. That’s when I found Stefaan Pouseele’s post about ISA Server and Windows Server 2003 service pack 2. Stefaan recommends not only disabling RSS and TCPA but also turning off TCP offload and the TCP chimney. […]