Thank you bruno and vickey,
VickeyOrana, I don't understand very well that paragraph, for my english it is a little bit complicated, but I'm going to explain you my NICs.
I have a DELL 2950 server, with ESXi 5.5. The server has 10 RJ45 ports 1000Mbps plus 1 DRAC RJ45 port (remote server management). Total 11 ethernet ports.
One of those 10 ports or nics (they are synonymous, right?) seems to be broken. Therefore only 9 nics work for ESXi.
I installed ESXi 5.5 and it recognized every nic in the server, and vmnics (0-9) appeared.
I configurated Nic teaming creating portgroups (same number than vmnics) to get load balancing. And now, one hour ago, I removed vmnic3 because it was the broken port.
It is supposed that putting each virtual machine in each portgroup I should get load balancing. That is, each virtual machine will use one nic of 1000Mbps. All of this without I configure manually each portgroup with each vmnic.
I don't know if I've get explain it well. I hope it.
Best regards. Thank you very much.