MAC (Media Access Control) address is a unique identifier assigned to network interfaces for communications on the physical network segment? (wikipedia). It is stored in the network interface card by the manufacturer.
The MAC address consists of a series of six pairs of numbers and letters separated by dashes. It’s a base-16 value (also called hexadecimal) [...]

Many HP ProLiant servers features PCI-Express technology. When some PCI-Express adapters are configured, the server may halt with a bluescreen. To avoid the bluescreen hardware malfunction, upgrade the server System ROM to the newest version and disable “Legacy SERR for PCI Express” using the ROM-Based Setup Utility (RBSU).