Local Area High Speed Networks

Individual/Group and Universal/Local Flag Bits

The two least significant bits in the first byte of a MAC address are the special flag bits that identify whether an address is:

• Individual (0) or group (1)

• Universal (0) or local (1)

Figure 2.2 shows the position of these important bits as they appear when each byte of a MAC address is written in binary with its most significant bit on the left.

Figure 2.2. Individual/group and universal/local flag bits.

Note

This is the normal mathematical order in which the bits in a byte are expressed. See Appendix B.