Which two protocols cannot load balance?

Which two protocols cannot load balance?

• A. GLBP and VRRP
• B. HSRP and GLBP
• C. HSRP and LACP
• D. HSRP and VRRP

Answer: (D)

Gateway redundancy protocols that spread traffic across multiple upstream routers are designed to share the load, while those that simply provide failover keep traffic flowing through one router at a time. The two redundancy protocols in question operate strictly in an active/standby mode: one router handles the traffic for the virtual IP, and the others wait to take over if that active one fails. Because only a single gateway forwards packets at any moment, there’s no real load sharing among multiple gateways with these protocols. In contrast, the Gateway Load Balancing Protocol is specifically built to use multiple active forwards, distributing traffic across several routers. So the two protocols that cannot load balance are HSRP and VRRP.

Gateway redundancy protocols that spread traffic across multiple upstream routers are designed to share the load, while those that simply provide failover keep traffic flowing through one router at a time. The two redundancy protocols in question operate strictly in an active/standby mode: one router handles the traffic for the virtual IP, and the others wait to take over if that active one fails. Because only a single gateway forwards packets at any moment, there’s no real load sharing among multiple gateways with these protocols. In contrast, the Gateway Load Balancing Protocol is specifically built to use multiple active forwards, distributing traffic across several routers. So the two protocols that cannot load balance are HSRP and VRRP.