Cisco Certified Network Professional 2025 – 400 Free Practice Questions to Pass the Exam

The MAC address format 0000.0c07.acxx in Hot Standby Router Protocol (HSRP) represents a unique identifier for a virtual router. Specifically, it indicates the group ID in hexadecimal format. In HSRP, the last two hexadecimal digits (acxx) encode the virtual router's group number, which is used by routers in the HSRP group to determine the active and standby router roles.

The significance of this hexadecimal representation lies in its ability to easily convey more data in a compact format, as hexadecimal digits represent a larger range of values compared to binary or octal. Thus, the last part of the MAC address, when converted from hex to decimal, reflects the HSRP group ID directly.

Understanding the representation of the group ID helps network professionals configure and troubleshoot HSRP effectively, ensuring high availability and redundancy in router setups. This knowledge enables better network management by providing clear identification and differentiation of virtual routers.