MAC address knowledge

1. the MAC address consists of six bytes, each of which is composed of 0-f. All the bytes that exceed f are invalid MAC addresses. The first three bytes represent the vendor, that is, the first three bytes can be used to determine which manufacturer produces the data, and the last three bytes are serial numbers.

2. the MAC address of all F is the broadcast address, and the IP address of all 0 is invalid (If your MAC address is completely 0, it means that the NIC is correct except for the problem)

3. The first byte is an odd number of multicast addresses, which cannot be used either.

X1: XX: xx
X3: XX: xx
X5: XX: xx
X7: XX: xx
X9: XX: xx
XB: XX: xx
XD: XX: xx
XF: XX: xx

Where X is the number 0-F

4. If the first byte is an even MAC address, we can use
X0: XX: xx
X2: XX: xx
X4: XX: xx
X6: XX: xx
X8: XX: xx
XA: XX: xx
XC: XX: xx
Xe: XX: xx

Where X is the number 0-F

Http://www.infocellar.com/networks/ip/mac-vs-ip.htm