Cisco CCNA mock exam questions sample test – Question 286

.Which statement is supported by the following output?

router# show ip protocols
Routing Protocol is “eigrp 3”
Sending updates every 90 seconds, next due in 24 seconds
EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
EIGRP maximum hopcount 100
EIGRP maximum metric variance 1
Redistributing: eigrp 3
Automatic network summarization is not in effect
Maximum path: 4
Routing for Networks:

A. EIGRP supports load-balancing over three equal-cost paths
B. EIGRP supports load-balancing over three unequal-cost paths
C. EIGRP supports load-balancing over four equal-cost paths
D. EIGRP supports load-balancing over four unequal-cost paths

Correct Answer: C

The Maximum path: 4 output indicates that Enhanced Interior Gateway Routing Protocol (EIGRP) will support round-robin load-balancing over four equal-cost paths. This is a default
setting, and is a true statement for most routing protocols (including RIP, OSPF and IS-IS). Equal-cost paths are different routes to the same destination network with identical metrics,
as determined by the routing protocol. Most routing protocols allow this maximum to be raised up to 16 with the maximum-paths command.
EIGRP has the additional benefit of allowing unequal cost load-balancing. With unequal cost load-balancing, the router can be configured to include less desirable (higher-metric)
paths in the routing table. The router will then send a balanced percentage of traffic over both the best route and the less desirable paths, such as sending two packets over the best
path plus one over a less desirable path. EIGRP will never perform unequal-cost load-balancing by default; it must be configured with a variance command. Therefore, you cannot
state that EIGRP supports load-balancing over unequal-cost paths in this example.
You cannot state that EIGRP will support load-balancing over three paths because the output displays the Maximum path: 4 value.
Routing Fundamentals
Configure, verify, and troubleshoot EIGRP for IPv4 (excluding authentication, filtering, manual summarization, redistribution, stub)
Cisco > Support > IP > IP Routing > Design > Design TechNotes > How Does Load Balancing Work? > Document ID: 5212
Cisco > Support > IP > IP Routing > Design > Design TechNotes > How Does Unequal Cost Path Load Balancing (Variance) Work in IGRP and EIGRP? > Document ID: 13677