Refer to the exhibit.
How will traffic be split between the routers, assuming that there are many hosts on this subnet?
A.
All traffic will be sent to the primary router (10.1.1.100).
B.
Traffic will be split equally between the two routers (10.1.1.100 and 10.1.1.101).
C.
Traffic will be split 25% (10.1.1.101) / 75% (10.1.1.100) between the two routers.
D.
Traffic will be split 75% (10.1.1.101) / 25% (10.1.1.100) between the two routers.
Explanation:
In addition to being able to set priorities on different gateway routers, GLBP allows a weighting
parameter to be set. Based on this weighting (compared to others in the same virtual router
group), ARP requests will be answered with MAC addresses pointing to different routers. Thus,load balancing is not based on traffic load, but rather on the number of hosts that will use each
gateway router. By default GLBP load balances in roundrobin fashion.
Load Balancing Modes
There will be three types of load balancing methods that can be configured:
Weighted
Host dependant
Round robin
Round Robin Load Balancing Algorithm
Each Virtual Forwarder MAC address takes turns being included in address resolution replies for
the virtual IP address. Round robin load balancing is recommended for situations where there are
a small number of end hosts.
If no load-balance algorithm is specified then GLBP will operate in a similar fashion to HSRP, i.e.
the AVG will only respond to ARP requests with its own VF MAC address, and all traffic will
therefore be directed to the AVG. No load balancing is defined using the following configuration
statement:
no glbp <glbp-group> load-balancing
The load balancing method will be set to default (round-robin) if any load balancing statement is
omitted.
Load Sharing
GLBP weighting has the ability to place a weight on each device when calculating the amount of
load sharing that will occur through MAC assignment. Each GLBP router in the group will advertise
its weighting and assignment. The AVG will act based on that value.
The only reason you would use this is if you have a larger circuit on the primary router than on the
backup router. So the higher weight of 160 will take twice as much traffic as the lower weight of
80. If the weights are
http://en.wikipedia.org/wiki/Gateway_Load_Balancing_Protocol
http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6550/
prod_presentation0900aecd801790a3_ps6600_Products_Presentation.html
http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6554/ps6600/
product_data_sheet0900aecd803a546c.html
http://www.cisco.com/en/US/docs/ios/12_2t/12_2t15/feature/guide/ft_glbp.html#wp1027129
