39633: Acronis Files Connect: poor performance and other network-related problems after you install Windows Server 2003 SP2 or the Scalable Networking Pack on a Windows Server 2003-based computer

Last update: 13-07-2017


Clients suffer from extremely slow performance (up to 8 times slower) when browsing or performing read/write operations against Windows 2003 Servers (SP1 or above).

The problem has been reported with Broadcom and other NIC Cards which are TOE (TCP Offload Engine) enabled.

Acronis Files Connect (formerly ExtremeZ-IP)

Mac clients connected to a EZIP share suffers slow performance compared to SMB.

MassTransit Server

Some clients sending files to a MassTransit server may suffer slow performance.

List of other symptoms from Microsoft KB Article:


You experience slow network performance.

Clients experience slow domain logons.

Network Address Translation (NAT) clients that are located behind Windows SBS 2003 experience intermittent connection failures.

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 cannot create an outgoing FTP connection from the server.
The DHCP Server service crashes.
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.

Steps to Reproduce:

refer to Microsoft Knowledge Base Article:



refer to Microsoft Knowledge Base Article:



Turn off TCP Chimney using netsh.exe (does not require a reboot)

  • Open a command prompt.
    • Click Start.
    • Click Run.
    • Type cmd.
    • Click OK.
  • At the command prompt, type the following and press enter:
    • netsh int ip set chimney DISABLED

Note: If you want to re-enable TCP Chimney type the following and press enter:

  • netsh int ip set chimney ENABLED

Also - please refer to Microsoft Knowledge Base Article's Step 3: Disable Receive Side Scaling Step 4: Disable offloading support http://support.microsoft.com/kb/936594


Contact your hardware vendor to check if there are any existing or forthcoming driver updates.