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I'm seeing some weird network problems on one of my machines, and I need some input :)

I have a host machine running Windows Server 2008 R2 and the Hyper-V role.

I have several guest machines running on this host including Windows 2008, 2008 R2 and one Windows 7.

On the 2008 and 2008 R2 machines network and internet access perform as I would expect. I have a 30/30 Mbit/s connection to the world.

However on the Windows 7 machine I get "extremely" slow upload speeds. Around 1 Mbit/s (100 KB/s). This is only when uploading to sites on the internet. Local network transfer between physical and virtual machines perform as expected. Download speeds are also fine, it's only upload to internet sites that perform badly.

Any idea what might be wrong?

-- Christian

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up vote 1 down vote accepted

Thanks for the effort guys.

I found this and it seems to solve my problems.

"Disable IPv4 Checksum Offload, IPv4 Large Send Offload and TCP Connection Offload (IPv4) on Server Core with Broadcom NICs"

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If I were you I'd check my lan card configuration (half duplex/full duplex, e.g.) and then a massive virus check. Just my two cents :)

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It could be that there is some traffic-shaping/QOS on the Gateway that is throttling the W7 machine.
you could try to shutdown the W2k8 Machines and config the w7 with the w2k8 machine ip.

Hope that helps

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