cisco ccna 200 301 requirements

cisco ccna 200 301 requirements.EIGRP supports load balancing among the 6 paths to the same destination network. By default, EIGRP performs only equal-overhead load balancing. In equal-overhead load balancing, EIGRP uses only the successor routes with the same metric value. However, you can enable EIGRP non-equal overhead load balancing, for which you can use the router subconfiguration mode commands variance and traffic-shareo To enable EIGRP non-equal overhead load balancing, use the router subconfiguration mode command varianceoRouter(config)# router eigrp autonomous_system_# Router(config-router)# variance multiplier multiplier is a positive integer that defaults to lo to use non-equal overhead paths (non-optimal paths), and the router converts the optimal path metric (feasible distance) by multiplier; if the non-optimal path metric (advertised distance) is less than this product, the router will add it to the routing table along with the optimal path. The range of possible values for multiplier is 1.128, and the default is 1, which means that EIGRP uses only the best path. If you increase the value of multipliervalue, the router will use all routes for which the metric is less than the product of the best path metric and multiplier. However, be sure to be careful not to set the value of multiplier too large; otherwise, a routing loop may result.Exam Essentials To equalize the load among non-equal overhead paths, use the command varianceo By default, only equal overhead paths are added to the routing table.Table 20.2 Example of an EIGRP topology used for variance calculationTo demonstrate the rationale, see Table 20.2. In this example, three neighbors advertise the same route to the current router - 192.168.1.0/24. The route advertised by Router B has the smallest feasible distance, so by default it will be added as a successor route to the current router's route The route advertised by Router B has the smallest feasible distance, so by default it will be added to the routing table of the current router as a successor. If multiplier is set to 2, the alternative route advertised by router C will be added to the routing table along with the feasible route advertised by router B: the FIX 60) of the route advertised by router C is less than twice the FD (40) of the route advertised by router B.(40) is twice as large. In other words, 60< 2x40(80)o will not use the path advertised by router D because the FD of that path is greater than twice the FD of the route advertised by router B.Be sure to be able to determine which additional routes will be added to the routing table based on the value of the multiplier.Routers are capable of load balancing intelligently. In other words, if there are two WAN links to the same destination network in the routing table (their bandwidths are 64 kbit/s and 128 kbit/s, respectively), it would not be reasonable to have each of these links carry half of the traffic. Doing so may result in saturation of the slower 64 kbit/s link. Instead, EIGRP balances the load based on the inverse of the path metric; for this example, about 1/3 of the traffic would be assigned to the 64kbit/s link and 2/3 of the traffic would be assigned to the 128-kbit/s link.To change this behavior, use the router subconfiguration mode command traffic-share.