Here it is.
http://www.vpeeling.com/?p=156
In case the page dissapear ... I copy the content here.
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-passthroughAuth = carries on currently logged on user credentials (use in conjunction with -s)
-s = server name
-u = username
-p = password
Here are a few examples:
"VpxClient.exe" -s esx01.company.com-u root -p MyPassword
"VpxClient.exe" -s esx01.company.com -passthroughAuth
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I like to create different shortcuts to the Client with the parameters already in, so I just need to double click to log in.
I also use it on the training kits, so students don't waste time on non-important things.