Extremely slow network/internet connection from within a virtual machine using the emulated NIC driver
I'm running W7 64 bit 7100. I've installed a number of VMs, including the XP mode and Windows Home Server. All VM's exhibit the same appalling slow connection onto the network via the "Intel 21140 PCI Fast Ethernet Adapter (Emulated)" My motherboard uses a Realtek PCIe GBE. To give you a comparison of performance from within the same VM......... I set up Home Server to backup a single partition on my 2nd hard drive, the VPC being hosted on my primary raid drive. The drive to be backed up was 16GB. After 24 minutes the progress on the backup was at 16%. Fortunately I have a USB external Multimedia Center which has a 100Mbs Ethernet connection. I connected this to my router, attached the USB device, installed the drivers off CD (ADM851X USB to Fast Ethernet), and disabled the "internal" "Intel 21140 PCI Fast Ethernet Adapter (Emulated)". My router issued a new IP address (seen as a new physical connection) and I re-ran the backup in exactly the same configuration. Result was that I did a 100% backup in 21 minutes. No matter which VPC I boot up, including the XP mode, the Intel 21140 PCI Fast Ethernet Adapter (Emulated) runs abysmally slow. Switching to the USB Ethernet and all runs sweetly. However, as I'd like the PC to boot up unattended to run backups for my networked PCs, the USB Ethernet does not auto attach. So unattended boot up and backup requires the "internal" NIC emulation to be loaded. Are there any fixes/updates to get the Intel 21140 PCI Fast Ethernet Adapter (Emulated) working at "normal" 100Mbps Lan speeds?
September 15th, 2009 6:26pm

Am I doomed to live life in the slow lane?!!! Jesting aside, is this issue a known problem being worked upon, or is a known problem and it will remain so? If it remains a problem I will have to find a new approach to handling "server" based backups in a VM.
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September 18th, 2009 12:24pm

Hi, In Windows 7 (host OS), please try the following: Disable "Large Send Offload" on the NIC: 1. Open an elevated command prompt and press Enter: netsh int ip set global taskoffload=disabled 2. Disable and re-enable the network interface. 3. Run the following command in an elevated command prompt to confirm the command above is successful: netsh int ip show offload Meanwhile, I would like to share the following with you: Slow performance when you try to access resources on your Virtual Server 2005 host computer from a guest virtual machine Hope this helps. Thanks.Nicholas Li - MSFT
September 18th, 2009 1:56pm

You absolute beauty! It worked a charm. Not only that, backing up the 16GB partition via WHS VM to another physical drive used the full 1GBit NIC capability and backed up the 16GB in 7.5 minutes! Brilliant! Thank you Nicholas! I'm glad I "bumped" my thread today!.
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September 19th, 2009 12:39am

Well, success was short lived as I now have another issue. Although I got the NIC working at super fast speeds, as soon as the VPC was shut down or hibernated, the VPC would not connect back to the Nic. A reboot of the PC didn't help. I then succeeded by adding additional connections in the VPC settings file, and moving the Nic to the 2nd "connection". The VPC booted up, found new hardware and connected. But again on shutdown/reboot it firmly refuses to connect to the network. It gets an IP from my router but the VPC will neither connect to the internet nor is it seen on the network. On occasions disabling and reenabling the integration features will make the Nic burst back into life, but not always. This is the VPC's settings C:\Documents and Settings\Administrator>ipconfig /all Windows IP Configuration Host Name . . . . . . . . . . . . : server2 Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Unknown IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : lan Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : lan Description . . . . . . . . . . . : Intel 21140-Based PCI Fast Ethernet Adapt er (Generic) Physical Address. . . . . . . . . : 00-03-FF-86-E9-B3 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : 192.168.1.73 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.1.254 DHCP Server . . . . . . . . . . . : 192.168.1.254 DNS Servers . . . . . . . . . . . : 192.168.1.254 Lease Obtained. . . . . . . . . . : 19 September 2009 16:19:28 Lease Expires . . . . . . . . . . : 20 September 2009 16:19:28 C:\Documents and Settings\Administrator>route print IPv4 Route Table =========================================================================== Interface List 0x1 ........................... MS TCP Loopback interface 0x10003 ...00 03 ff 86 e9 b3 ...... Intel 21140-Based PCI Fast Ethernet Adapter (Generic) =========================================================================== =========================================================================== Active Routes: Network Destination Netmask Gateway Interface Metric 0.0.0.0 0.0.0.0 192.168.1.254 192.168.1.73 20 127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1 192.168.1.0 255.255.255.0 192.168.1.73 192.168.1.73 20 192.168.1.73 255.255.255.255 127.0.0.1 127.0.0.1 20 192.168.1.255 255.255.255.255 192.168.1.73 192.168.1.73 20 224.0.0.0 240.0.0.0 192.168.1.73 192.168.1.73 20 255.255.255.255 255.255.255.255 192.168.1.73 192.168.1.73 1 Default Gateway: 192.168.1.254 =========================================================================== Persistent Routes: None Has anyone else experienced this irksome problem with no connectivity at all either onto the network or internet? EDIT: Manually assigning IP etc does not work either. I just cannot get the VM to recognise the emulated NIC to the host.
September 19th, 2009 6:31pm

I think I've found my problem...... The programs I was trying to install or run under the VM were not 100% compatible and appeared to interfere with the network/tcpip/dns settings. I confirmed this when I ha dhad IE open and working on the web and then I tried to set up WHS Remote Access which sets itself up with my router. As soon as that "discovery" process started the IE session was lost and would not return even after shutting down WHS. So although some have said they have got WHS working, I don;t think it is for me. :(
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September 20th, 2009 4:04am

I ran into this problem today and just wanted to thank you for the link. It's so rare (it seems) that this type of diddling actually fixes anything :-) FYI, I followed Workaround 3 on the referenced link. The wording of the properties was slightly different for me: IPv4 Checksum and Large Send Offload(IPv4). My PC has a Realtek PCIe GBE Family Controller in it.
November 1st, 2009 11:22pm

Nicholas,I was likewise having problems with the performance of copying files from host OS to guest virtual machine over a network share. Horrible throughput, but only from Host to Guest. The guest VM could copy from anywhere without any problems, other systems could copy to Guest VM without any problems, but host-guest was terribly slow. Applied your offloading netsh command and it instantly fixed the problem without a reboot.Windows 7 HostWindows 7 Guest OSThanks for your solution!-Chris
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December 7th, 2009 9:39pm

Hi Chris, Glad to know this helps. In the future, if you experience any issues regarding our products or if you have some feedbacks, you are also welcome to post a new thread in our forum. It is always our pleasure to be of assistance. Thanks again! Have a great day!Nicholas Li - MSFT
December 8th, 2009 4:47am

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