You can not configure physical NICs on ESXi like on Windows. Physical NICs on ESXi also don't get IP addresses.
You already have some vSwitch configured and some portgroups on ESXi I suppose. You can add new NIC to existing vSwitch/portgroups for load balancing and redundancy through "NIC teaming policy" tab in vSwitch settings.
But it won't have its own IP address, it would just another physical window to outer network.
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MCSA, MCTS Hyper-V, VCP 3/4, VMware vExpert '2009
http://blog.vadmin.ru