The answer is that R3 will install both routes and load balance across them. This occurs because OSPF equal-cost load balancing is a default behavior: when a router learns multiple routes to the same destination with an identical metric, it installs all of them into the routing table, up to the platform’s default maximum-paths value (typically four on Cisco IOS). The router then distributes traffic across these equal-cost links, improving bandwidth utilization without requiring manual intervention. On the CCNA 200-301 v2 exam, this concept tests your understanding of OSPF’s metric-based path selection and the default behavior of the routing table. A common trap is assuming OSPF always picks a single best path, but the protocol is designed to leverage redundancy when costs match. Remember the mnemonic “Equal cost, both tossed” — if the metrics tie, both routes get installed and traffic gets shared.
CCNA IP Routing Practice Question
This 200-301 practice question tests your understanding of ip routing. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. A key principle to apply: oSPF uses the Dijkstra algorithm to calculate the shortest path to each destination network based on link-state information.. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Exhibit
R3 routing candidates for 10.50.0.0/16:
via 10.0.23.2 cost 20
via 10.0.34.4 cost 20
Both learned as OSPF intra-area routes
Exhibit: R3 learns 10.50.0.0/16 by OSPF through two equal-cost paths. What will R3 do by default?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Install both routes and load balance
When OSPF has equal-cost routes to the same destination, the router installs multiple paths and can load balance across them, assuming the platform supports the default maximum-paths value.
Key principle: OSPF uses the Dijkstra algorithm to calculate the shortest path to each destination network based on link-state information.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
OSPF uses the Dijkstra algorithm to calculate the shortest path to each destination network based on link-state information.
✗
Choose the route from the neighbor with the highest router ID only
Why it's wrong here
That is not the standard OSPF path-selection rule for equal costs.
When this WOULD be correct
In a different scenario where the question specifies that OSPF is configured to select routes based on router ID due to a specific policy or configuration, this option could be correct. For example, if the exam question stated that OSPF was modified to prefer routes based on router ID in a unique network setup.
✗
Install only one route because OSPF does not support ECMP
In a different scenario where the question specifies a routing protocol that does not support ECMP, such as RIP, the correct answer could be that only one route is installed. For example, if the question stated that R3 learns routes via RIP instead of OSPF, this option would be accurate.
✗
Prefer the path with the lower next-hop IP address
Why it's wrong here
Next-hop IP address is not the deciding factor here.
When this WOULD be correct
In a scenario where a routing protocol explicitly states to prefer paths based on the next-hop IP address, such as in a question about EIGRP or a custom routing policy, this option would be correct. For example, if the question specified that only one route should be chosen based on the next-hop IP address, then this option would apply.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓Install both routes and load balanceCorrect answer▾
Why this is correct
Equal-cost OSPF paths are installed by default.
✗Choose the route from the neighbor with the highest router ID onlyWrong answer — click to see why▾
Why this is wrong here
This option is incorrect because OSPF does not select routes based solely on the router ID; it uses metrics such as cost to determine the best path. In the context of equal-cost multi-path (ECMP), both routes would be installed by default.
★ When this WOULD be the correct answer
In a different scenario where the question specifies that OSPF is configured to select routes based on router ID due to a specific policy or configuration, this option could be correct. For example, if the exam question stated that OSPF was modified to prefer routes based on router ID in a unique network setup.
Why candidates choose this
Candidates may find this option tempting due to a common misconception that OSPF prioritizes router IDs in route selection, especially if they have encountered scenarios where router IDs are relevant in other protocols or configurations.
✗Install only one route because OSPF does not support ECMPWrong answer — click to see why▾
Why this is wrong here
This option is incorrect because OSPF does support Equal-Cost Multi-Path (ECMP) routing, allowing multiple routes to be installed in the routing table when they have the same cost.
★ When this WOULD be the correct answer
In a different scenario where the question specifies a routing protocol that does not support ECMP, such as RIP, the correct answer could be that only one route is installed. For example, if the question stated that R3 learns routes via RIP instead of OSPF, this option would be accurate.
Why candidates choose this
Candidates may choose this option due to a misunderstanding of OSPF's capabilities, mistakenly believing that OSPF does not allow multiple equal-cost routes due to confusion with other protocols that have similar limitations.
✗Prefer the path with the lower next-hop IP addressWrong answer — click to see why▾
Why this is wrong here
This option is incorrect because OSPF does not prioritize routes based solely on the next-hop IP address; it uses equal-cost multi-path (ECMP) routing to install multiple routes when they have the same cost.
★ When this WOULD be the correct answer
In a scenario where a routing protocol explicitly states to prefer paths based on the next-hop IP address, such as in a question about EIGRP or a custom routing policy, this option would be correct. For example, if the question specified that only one route should be chosen based on the next-hop IP address, then this option would apply.
Why candidates choose this
Candidates may find this option tempting due to a common misconception that routing protocols always prefer lower next-hop IP addresses, which is a principle in some protocols but not in OSPF's ECMP context.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is believing that OSPF will choose only one route when multiple equal-cost paths exist, often assuming it picks the route from the neighbor with the highest router ID or the path with the lowest next-hop IP address. This misconception leads to incorrect answers because OSPF’s path selection process installs all equal-cost routes by default. Misunderstanding this behavior can cause candidates to overlook OSPF’s load balancing capability and mistakenly select options that describe single-route preferences, which do not apply to equal-cost multipath scenarios.
Detailed technical explanation
How to think about this question
OSPF (Open Shortest Path First) is a link-state routing protocol that calculates the shortest path to each network using the Dijkstra algorithm. When a router learns multiple routes to the same destination with equal cost metrics, it can install multiple paths in its routing table. This capability allows OSPF to perform equal-cost multipath (ECMP) routing, which balances traffic across multiple links to optimize bandwidth and redundancy.
By default, Cisco IOS routers running OSPF install all equal-cost routes up to a platform-specific maximum (commonly four or more) into the routing table. The router then load balances traffic across these paths, distributing packets evenly or based on per-flow hashing. This behavior improves network utilization and resilience without requiring manual configuration.
A common exam trap is assuming OSPF selects a single route based on arbitrary criteria like the highest router ID or lowest next-hop IP address. These are not OSPF path selection rules for equal-cost routes. Instead, OSPF installs all equal-cost paths by default, and only when paths have unequal costs does it prefer the lowest cost route. Understanding this prevents misinterpretation of OSPF behavior and ensures accurate routing knowledge for the CCNA exam.
KKey Concepts to Remember
OSPF uses the Dijkstra algorithm to calculate the shortest path to each destination network based on link-state information.
When OSPF learns multiple equal-cost routes to the same destination, it installs all these routes into the routing table by default.
OSPF supports equal-cost multipath (ECMP) routing, allowing load balancing across multiple paths with the same metric.
Cisco routers have a default maximum number of equal-cost paths they can install, typically four or more, depending on the platform.
OSPF does not select a single route based on the highest router ID or lowest next-hop IP address when multiple equal-cost paths exist.
Load balancing in OSPF distributes traffic evenly or per-flow across all installed equal-cost routes to optimize bandwidth usage.
Unequal-cost routes in OSPF result in the router preferring the path with the lowest cost metric, ignoring higher cost paths.
Understanding OSPF ECMP behavior helps avoid common exam traps related to path selection and routing table installation.
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.
Key takeaway
OSPF uses the Dijkstra algorithm to calculate the shortest path to each destination network based on link-state information.
Real-world example
How this comes up in practice
A network engineer at a university connects two campus buildings via a fibre link. Both routers run OSPF, but no adjacency forms — even though both routers can ping each other. The engineer finds one router is in area 0 and the other in area 1. OSPF adjacency requires matching area numbers, hello/dead timers, and network type. IP reachability alone is not enough.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 200-301 question in full detail.
Review oSPF uses the Dijkstra algorithm to calculate the shortest path to each destination network based on link-state information., then practise related 200-301 questions on the same topic to reinforce the concept.
IP Routing — This question tests IP Routing — OSPF uses the Dijkstra algorithm to calculate the shortest path to each destination network based on link-state information..
What is the correct answer to this question?
The correct answer is: Install both routes and load balance — When OSPF has equal-cost routes to the same destination, the router installs multiple paths and can load balance across them, assuming the platform supports the default maximum-paths value.
What should I do if I get this 200-301 question wrong?
Review oSPF uses the Dijkstra algorithm to calculate the shortest path to each destination network based on link-state information., then practise related 200-301 questions on the same topic to reinforce the concept.
What is the key concept behind this question?
OSPF uses the Dijkstra algorithm to calculate the shortest path to each destination network based on link-state information.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This 200-301 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 200-301 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.