Monitoring VM network

Hi,

I just installed ESXi 5.1 and try to monitor virtual machine.

I can't find where I can get the incoming and transmitted bytes count for a virtual machine port.

I found how to get it for a physical port with vsish -e cat /net/pNics/vmnic0/stats | grep bytes, but for a virtual machine port I just found how to retrieve the packets/s and bandwith values (with esxtop : PKTTX/s, MbTX/s, PKTRX/s, MbRX/s).

Does somebody knows how to get that information for a virtual port ?

Thx for any suggestions.