What Does GLBP Mean in 200-301?
Full form: Gateway Load Balancing Protocol
Also known as: Gateway Load Balancing Protocol
Quick Definition
A Cisco proprietary FHRP that provides redundancy and load balancing using multiple virtual MACs.
Full Definition
GLBP is a Cisco-proprietary FHRP that goes beyond simple failover. It elects one Active Virtual Gateway (AVG) to assign virtual MAC addresses, and multiple Active Virtual Forwarders (AVFs) that each own one virtual MAC and actively forward traffic. Hosts in the subnet ARP for the gateway and receive different virtual MACs in round-robin order, spreading load across all routers simultaneously. This is GLBP's key advantage over HSRP and VRRP.
Exam Trap — Don't Get Fooled
GLBP provides load balancing. HSRP and VRRP do not — in HSRP/VRRP, only the Active/Master forwards traffic, and the Standby/Backup idles unless the Active fails.
Related 200-301 Terms
A Cisco proprietary FHRP that provides a virtual IP gateway shared by an active and standby router.
A category of protocols that provide a virtual gateway IP shared across multiple routers for redundancy.
An open-standard FHRP where routers elect a Master that owns the virtual IP and responds to ARP requests.
Frequently Asked Questions
What does GLBP mean on the 200-301 exam?
GLBP is a Cisco-proprietary FHRP that goes beyond simple failover. It elects one Active Virtual Gateway (AVG) to assign virtual MAC addresses, and multiple Active Virtual Forwarders (AVFs) that each own one virtual MAC and actively forward traffic. Hosts in the subnet ARP for the gateway and receive different virtual MACs in round-robin order, spreading load across all routers simultaneously. This is GLBP's key advantage over HSRP and VRRP.
How does GLBP appear as a trap on the 200-301?
GLBP provides load balancing. HSRP and VRRP do not — in HSRP/VRRP, only the Active/Master forwards traffic, and the Standby/Backup idles unless the Active fails.
How important is GLBP on the 200-301 exam?
GLBP falls under the Routing domain of the 200-301 exam. Understanding it in context with related terms like hsrp and vrrp is essential for answering scenario-based questions correctly.