Cisco Certified Network Associate (CCNA) Practice Exam

Which protocol uses a priority-based scheme for electing a router master?

1. Gateway Load Balancing Protocol (GLBP)

2. Hot Standby Router Protocol (HSRP)

3. Virtual Router Redundancy Protocol (VRRP)

4. Open Shortest Path First (OSPF)

The correct answer is: Virtual Router Redundancy Protocol (VRRP)

The correct answer is Gateway Load Balancing Protocol (GLBP). This protocol utilizes a priority-based scheme to elect a master router from a group of routers that are configured to work together as a virtual router. In GLBP, routers share the load of handling packets by allowing multiple active routers, in contrast to other redundancy protocols that typically have a single active router and backup routers. This priority-based election process ensures that the router with the highest priority becomes the master, distributing the traffic more evenly across multiple gateways, which can enhance fault tolerance and load distribution. The other protocols listed have different operational mechanisms. For example, Hot Standby Router Protocol (HSRP) designates a primary router, with others standing by as backups, and does not actively load balance traffic among multiple routers. Similarly, Virtual Router Redundancy Protocol (VRRP) operates on a master/backup basis and relies on a priority system to choose the master but doesn’t actively balance the load across multiple routers like GLBP does. Open Shortest Path First (OSPF), being a routing protocol rather than a redundancy protocol, does not involve a master election process for redundancy in the same way.