[vbox-dev] bridged network between VMs on same host is very slow

Geoff Nordli geoffn at gnaa.net
Fri Jun 24 17:49:19 GMT 2011

>-----Original Message-----
>From: vbox-dev-bounces at virtualbox.org [mailto:vbox-dev-
>bounces at virtualbox.org] On Behalf Of Aleksey Ilyushin
>Sent: Friday, June 24, 2011 9:22 AM
>To: vbox-dev at virtualbox.org
>Subject: Re: [vbox-dev] bridged network between VMs on same host is very
>>>> Data transfer between VMs on the same host is very, very slow ~16KB/s.
>> I am finding slowness with Windows guest to Linux Host and also
>> general slowness on network access from client pc to any guest.
>There is a performance issue with Windows guests since they tend to use
>packets with segmentation offloading. They will always be slower than Linux
>guests but we are working on narrowing the gap.
>> Speeds were terrible using a Realtek PCI card 8169, something like
>> 4.25mbts but perhaps a hardware incompatibility.
>What are the offloading settings for the card (sudo ethtool -k

The part I find confusing is the network speeds to other resources (besides
to VMs located on the same host) is fine, if it was a Windows guest issue,
wouldn't it affect all traffic? 

These are Intel(R) PRO/1000 Network cards on a server class motherboard.  

Offload parameters for eth0:
rx-checksumming: on
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: on
udp-fragmentation-offload: off
generic-segmentation-offload: on
generic-receive-offload: off
large-receive-offload: off



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