Which command enables GLBP on an interface?

A. glbp

B. glbp 10 ip 192.168.1.1

C. standby mode glbp
D. switchport mode glbp

Explanation:

The glbp ip interface configuration command enables Group Load Balancing Protocol (GLBP). The syntax for this command is as follows:

switch(config-if)# glbp group-number ip ip-address

The following example activates GLBP for group 5 on Fast Ethernet interface 1/0. The virtual IP address to be used by the GLBP group is set to 10.5.5.5. The default gateway of each host should be set to the virtual IP address.

switch(config)# interface FastEthernet 1/0
switch(config-if)# ip address 10.5.5.1 255.255.255.0
switch(config-if)# glbp 5 ip 10.5.5.5

GLBP is a Cisco-designed protocol that provides for the dynamic use of redundant routers in a broadcast network. It differs from HSRP and VRRP in that it is not necessary to configure multiple groups to fully use redundant paths or routers. GLBP has a configurable load-balancing mechanism that will distribute the use of redundant gateways servicing a broadcast network such as an Ethernet LAN. When a host issues an ARP to resolve its gateway’s MAC address, the active virtual gateway (AVG) will respond with the virtual MAC address of a selected active virtual forwarder (AVF). The AVG will perform load balancing by varying which virtual MAC it selects to use in the response. The AVF will own that assigned virtual MAC as long as the gateway is active. If an AVF becomes unable to provide service as gateway, then another AVF can assume ownership of the virtual MAC.

Objective:
Infrastructure Services
Sub-Objective:
Configure and verify first-hop redundancy protocols

References:
Cisco > Cisco IOS IP Application Services Configuration Guide, Release 12.4 > Part 1: First Hop Redundancy Protocols > Configuring GLBP