ESX NIC Teaming

http://kb.vmware.com/kb/1001938

http://kb.vmware.com/kb/1004048

http://www.tcpdump.com/kb/virtualization/vmware-esx-server/esx-nic-teaming/intro.html

http://blog.scottlowe.org/2006/12/04/esx-server-nic-teaming-and-vlan-trunking/

Read official docs first.