Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
Which statement best describes equal-cost multipath behavior in routing?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
The router may install multiple equally good routes to the same destination and use them for forwarding
This is correct because equal-cost multipath allows use of more than one equivalent route.
B
Distractor review
The router always discards all but the first route learned
This is wrong because many routing platforms support equal-cost multipath.
C
Distractor review
Equal-cost multipath means every route source is trusted equally
This is wrong because route-source trust is a separate administrative-distance concept.
D
Distractor review
Equal-cost multipath works only when no routing table exists
This is wrong because ECMP is a routing-table behavior, not the absence of one.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is the misconception that routers discard all but the first learned route to a destination, ignoring the presence of equal-cost multipath. Candidates may incorrectly assume that only one route is ever installed, leading to wrong answers. This mistake arises from confusing route selection with route installation and from not recognizing that many Cisco routing protocols actively support ECMP. Misunderstanding this can cause candidates to overlook how routers distribute traffic and maintain redundancy, resulting in incorrect conclusions about routing behavior.
Technical deep dive
How to think about this question
Equal-cost multipath (ECMP) is a routing technique that allows a router to install and use multiple routes to the same destination when those routes have identical metrics or costs. This capability enables the router to distribute traffic across several paths, improving bandwidth utilization and providing redundancy. In Cisco routing protocols like OSPF and EIGRP, ECMP is supported and commonly used to optimize network performance and resilience. When a router receives multiple routes to a destination with the same cost, it compares their metrics and administrative distances. If these values are equal, the router installs all these routes into the routing table and uses them simultaneously for forwarding packets. The router typically balances traffic using per-packet or per-flow load balancing methods, depending on the platform and configuration. This behavior contrasts with selecting a single best route, which would leave other equal-cost paths unused. A common exam trap is assuming that routers always select only one route to a destination, ignoring ECMP capabilities. Some candidates mistakenly believe that multiple equal-cost routes are discarded except for the first learned. However, Cisco routers actively use ECMP to enhance network efficiency. Understanding this behavior is crucial for interpreting routing tables and troubleshooting load balancing issues in real networks.
KKey Concepts to Remember
- Equal-cost multipath allows a router to install multiple routes with the same metric to the same destination for simultaneous use.
- Routing protocols like OSPF and EIGRP support ECMP by advertising and installing multiple equal-cost routes in the routing table.
- The router compares route metrics and administrative distances to determine if multiple routes qualify for ECMP installation.
- When multiple equal-cost routes exist, the router balances traffic across these paths to improve load distribution and redundancy.
- ECMP behavior prevents the router from discarding all but one route when multiple equal-cost routes are available.
- Administrative distance influences route selection but does not affect the router’s ability to use ECMP for equal-cost routes.
- ECMP is a routing-table behavior that requires an existing routing table and does not function without it.
- Understanding ECMP helps avoid misinterpretation of routing table entries and improves troubleshooting of routing and load balancing.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
CCNA subnetting practice questions
Practise IPv4 subnetting, CIDR, masks, host ranges and subnet selection.
CCNA OSPF practice questions
Practise OSPF neighbours, router IDs, metrics, areas and routing-table interpretation.
CCNA VLAN practice questions
Practise VLANs, access ports, trunks, allowed VLANs and switching scenarios.
CCNA STP practice questions
Practise spanning tree, root bridge election, port roles and STP troubleshooting.
CCNA EtherChannel practice questions
Practise LACP, PAgP, port-channel behaviour and bundle requirements.
CCNA ACL practice questions
Practise standard and extended ACLs, permit/deny logic and traffic filtering.
CCNA NAT practice questions
Practise static NAT, dynamic NAT, PAT and inside/outside address translation.
CCNA DHCP practice questions
Practise DHCP scopes, relay, leases and troubleshooting.
CCNA show ip route practice questions
Practise routing-table output, longest-prefix match, AD and route selection.
CCNA show interfaces trunk practice questions
Practise trunk verification and VLAN forwarding across switches.
CCNA wireless security practice questions
Practise WLAN security, authentication and wireless architecture concepts.
CCNA IPv6 practice questions
Practise IPv6 addressing, routes, neighbour discovery and common IPv6 exam traps.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
Equal-cost multipath allows a router to install multiple routes with the same metric to the same destination for simultaneous use.
What is the correct answer to this question?
The correct answer is: The router may install multiple equally good routes to the same destination and use them for forwarding — Equal-cost multipath allows a router to use more than one path to the same destination when those paths are considered equally good by the routing logic. In plain language, if the router sees multiple valid routes with the same cost or equivalent preference, it may install more than one and share traffic across them. This can improve redundancy and load distribution without requiring one path to sit idle. This concept is important because learners often assume the router must always choose only one path. In reality, many routing environments support multiple equal paths simultaneously. The correct answer is the one that captures this multi-path forwarding behavior.
What should I do if I get this 200-301 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
Discussion
Loading comments…
Sign in to join the discussion.