You must understand MAC addresses assignment if you perform one of the following actions:
Define static Address Resolution Protocol (ARP) entries for IP addresses in the switch
Use a network analyzer to decode network traffic
Each chassis is assigned a base number of MAC addresses with a number reserved for ports and other internal purposes, and the remainder assigned to routable VLANs.
| Base assignment | Reserved | Assigned to routable VLANs | 
|---|---|---|
| 1,024 | First 256 | remaining 768 | 
Virtual MAC addresses are the addresses assigned to VLANs. The system assigns a virtual MAC address to a VLAN when it creates the VLAN. The MAC address for a VLAN IP address is the virtual MAC address assigned to the VLAN.