I have an ESXi 5.1 server with two Intel 82574L NICs on a Asus Z8NA-D6C motherboard. Both NICS worked perfectly and were detected fine until I added an additional two nics on two PCIe slots on the motherboard. Since I have done this vmnic0 has disappeared. The odd part is that when I do an lspci it shows all four nics, and sometimes it shows [vmnic0] after the fist Intel NIC, however when I do an esxcli command to list the nics, or login using vSphere it only shows vnmic1, 2, and 3. vmnic0 is even in the esx.conf file, and I can't find any boot errors for initialization. I've even tried re-installing a fresh OS but it does the same thing.
Any help is greatly appreciated!