Bridged --> poor network performance, NAT --> normal network performance

[HansSchmidt]

Hi there again,

Two day's ago I wrote:

I'm experiancing dramatic poor networkperformance (only several kb/s) on VM's that acces data on shares on the hostcomputer. The VM's (2 x Vista 32 bit, 1 x XP) are made under WS 6.5. I've just changes hardware on the host.. I've switched over to VMWare server for diagnostics but it's all the same with that version.

The host is a freshly installed Vista64 SP2 (i7-860/8Gb Ram). Does anyone has some suggestions. I'm out of them

Since then I've discovered that when I change the network adapters in my VM's to NAT it worksjust fine. Shares on the host are all accessible with normal performance. Downside is that the VM's are only accessible from the console of the host and that not what want. Changing the setting back to bridging brings the problem back, eg performance drops to only several kb per second. Does anyone have a clue what's going on here.

Regards Hans

[mdford]

You might want to change the title - the "-->" appears to be confusing the site so the title shows up as just "normal network performance" - something we both are trying to achieve!

I upgraded to Win7 RTM and reinstalled Workstation 6.5.3 and everything was fine - or so I thought. I recently discovered that my VMs are not running at gigabit speeds any more - but I'm not completely sure they did before the upgrade either. Transfers from host to any other system on my LAN is gigabit. From WinXP VM to Host (bridged) is ~100Mb, from Win7 to host (bridged) is ~116Mb, using NAT it's ~170Mb.

I've found several posts for earlier versions of Workstation that say to disable TCP offloading, Large Send Offloading, and other settings, but none of that helps. No matter what I try I cannot get gigabit speeds from any of my VMs (running WinXP, Server2k3, Server2k8, or Win7). Host is running Windows 7 x64 RTM.

Has anyone gotten "normal" network performance using a similar setup??

Michael

[HansSchmidt]

Michael,

First of all my apologies for responding so late. You remarks about the title are correct, and i've seen myself but didn't know how to change it.

The speeds you are talking about are great. a gbit LAN won't give you more than the speeds you are talking about. It strange though that NAT give you more performance than bridging. That's strange. All the remarks about TCP offloading i've read to, but didn't do anything with it. I use my onboard very simple NIC and couldn't imagine the proble laying there.

The speeds in bridging mode that i reach are no more than several kb's....So i'v solved it with NAT en opening ports....it works but some of my software can't work with NAT zo i stillen wan't to solve it. A collegue of mine suggested switching of QOS. I haven't tried is yet. It's a strange issue and also that so little people react in the forum.

Thanks for your reply. I will keep you posted.

Hans