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: administrative distance (AD) determines the trustworthiness of routing information sources when multiple protocols advertise the same destination prefix.. 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.
Which statement best describes the purpose of administrative distance when two different routing sources advertise the same prefix?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
It ranks the trustworthiness of different route sources advertising the same destination.
Administrative distance helps the router decide which route source to trust more. In plain language, if the same network is learned from two different sources, such as OSPF and a static route, the router needs a source-preference rule before it can install one. Administrative distance provides that rule.
This is different from a metric, which typically compares multiple paths inside the same routing protocol. The correct answer is the one focused on source trust rather than path cost inside one protocol.
Key principle: Administrative distance (AD) determines the trustworthiness of routing information sources when multiple protocols advertise the same destination prefix.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
It ranks the trustworthiness of different route sources advertising the same destination.
The clue word "best" in the question point toward this answer.
Related concept
Administrative distance (AD) determines the trustworthiness of routing information sources when multiple protocols advertise the same destination prefix.
If the exam question asked about the process of determining the next hop in a Layer 2 network, specifically focusing on how devices identify each other using MAC addresses, then this option could be correct. For example, a question might ask how a switch learns the MAC address of a device to forward frames correctly.
If the question asked about the configuration of VLANs on a switch and how to identify the native VLAN for trunk links, then option C would be correct. For example, a question could ask, 'What defines the native VLAN for a trunk link on a switch?'
✗
It defines the subnet mask of the learned route.
Why it's wrong here
This is wrong because prefix length is part of the route itself, not the administrative-distance function.
When this WOULD be correct
In a question asking about the attributes of routing protocols, if it specifically inquires about how subnet masks are assigned to routes, this option could be correct. For example, a question could ask which parameter specifies the subnet mask when a router learns a route from a specific protocol.
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.
✓It ranks the trustworthiness of different route sources advertising the same destination.Correct answer▾
Why this is correct
This is correct because administrative distance is a source-preference value.
✗It determines the MAC address of the next hop.Wrong answer — click to see why▾
Why this is wrong here
This option is wrong because administrative distance is not related to determining MAC addresses; it is a metric used to rank the trustworthiness of routing sources for IP routes. MAC addresses are used at Layer 2, while administrative distance operates at Layer 3.
★ When this WOULD be the correct answer
If the exam question asked about the process of determining the next hop in a Layer 2 network, specifically focusing on how devices identify each other using MAC addresses, then this option could be correct. For example, a question might ask how a switch learns the MAC address of a device to forward frames correctly.
Why candidates choose this
Candidates may choose this option due to a misunderstanding of routing concepts and the role of MAC addresses in network communication, leading them to mistakenly associate administrative distance with next-hop determination.
✗It specifies the native VLAN for trunk links.Wrong answer — click to see why▾
Why this is wrong here
Option C is incorrect because administrative distance is related to routing protocols and their trustworthiness, not to VLAN configurations or trunk links. The native VLAN is a separate concept that pertains to how VLANs are managed on trunk ports.
★ When this WOULD be the correct answer
If the question asked about the configuration of VLANs on a switch and how to identify the native VLAN for trunk links, then option C would be correct. For example, a question could ask, 'What defines the native VLAN for a trunk link on a switch?'
Why candidates choose this
Candidates may find option C tempting because it relates to VLAN concepts, which are commonly discussed in networking. If they misinterpret the question as being about VLANs rather than routing, they might incorrectly choose this option.
✗It defines the subnet mask of the learned route.Wrong answer — click to see why▾
Why this is wrong here
This option is wrong because administrative distance does not define the subnet mask of a learned route; rather, it is used to rank the trustworthiness of different routing sources for the same destination prefix.
★ When this WOULD be the correct answer
In a question asking about the attributes of routing protocols, if it specifically inquires about how subnet masks are assigned to routes, this option could be correct. For example, a question could ask which parameter specifies the subnet mask when a router learns a route from a specific protocol.
Why candidates choose this
Candidates may find this option tempting because they associate routing concepts with subnetting and may confuse the role of administrative distance with other routing attributes, leading to a misinterpretation of the question.
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 mistaking administrative distance for routing metrics or other unrelated concepts like VLAN configuration or MAC address resolution. Candidates often confuse AD with the metric used inside routing protocols to select the best path among multiple routes from the same protocol. However, administrative distance operates at a higher decision level, comparing route sources rather than path costs. Selecting answers that describe subnet masks, VLANs, or MAC addresses as AD functions is incorrect because AD only ranks the trustworthiness of routing sources, not Layer 2 or subnetting details.
Detailed technical explanation
How to think about this question
Administrative distance is a numerical value assigned by Cisco routers to rate the reliability or trustworthiness of routing information received from different routing protocols or sources. It acts as a preference ranking system that helps the router decide which route to install in its routing table when multiple routes to the same destination prefix exist from different routing sources. Each routing protocol has a default administrative distance; for example, directly connected interfaces have an AD of 0, static routes 1, EIGRP 90, OSPF 110, and RIP 120. The lower the AD, the more preferred the route source.
When a router receives multiple advertisements for the same network prefix from different routing protocols, it compares their administrative distances first. The route with the lowest AD is selected and installed in the routing table, regardless of the metric values used within each protocol. This selection process ensures that the router trusts the most reliable source before considering path cost or metric. If two routes have the same AD, the router then compares the metrics within the routing protocol to select the best path.
A common exam trap is confusing administrative distance with routing metrics or other network concepts like VLANs or MAC address resolution. Administrative distance is strictly about source trustworthiness, not path cost or Layer 2 addressing. Practically, understanding AD is crucial in multi-protocol environments where static routes, EIGRP, OSPF, or other protocols coexist. Misunderstanding AD can lead to unexpected routing behavior, such as a less optimal route being installed or routing loops if the router trusts an unintended source.
KKey Concepts to Remember
Administrative distance (AD) determines the trustworthiness of routing information sources when multiple protocols advertise the same destination prefix.
Routers use administrative distance to select the best route among different routing protocols before considering metrics within a single protocol.
A lower administrative distance value indicates a more preferred and trusted route source by the router.
Static routes typically have a lower administrative distance than dynamic routing protocols, making them more preferred if both advertise the same prefix.
Administrative distance is a router-internal value and does not affect the actual routing metric or path cost used within routing protocols like OSPF or EIGRP.
When two routes to the same destination have equal administrative distance, the router uses the routing protocol metric to choose the best path.
Administrative distance does not influence MAC address resolution, VLAN configuration, or subnet mask determination.
Understanding administrative distance helps prevent routing conflicts and ensures predictable routing behavior in multi-protocol environments.
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
Administrative distance (AD) determines the trustworthiness of routing information sources when multiple protocols advertise the same destination prefix.
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 administrative distance (AD) determines the trustworthiness of routing information sources when multiple protocols advertise the same destination prefix., then practise related 200-301 questions on the same topic to reinforce the concept.
IP Routing — This question tests IP Routing — Administrative distance (AD) determines the trustworthiness of routing information sources when multiple protocols advertise the same destination prefix..
What is the correct answer to this question?
The correct answer is: It ranks the trustworthiness of different route sources advertising the same destination. — Administrative distance helps the router decide which route source to trust more. In plain language, if the same network is learned from two different sources, such as OSPF and a static route, the router needs a source-preference rule before it can install one. Administrative distance provides that rule.
This is different from a metric, which typically compares multiple paths inside the same routing protocol. The correct answer is the one focused on source trust rather than path cost inside one protocol.
What should I do if I get this 200-301 question wrong?
Review administrative distance (AD) determines the trustworthiness of routing information sources when multiple protocols advertise the same destination prefix., then practise related 200-301 questions on the same topic to reinforce the concept.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Administrative distance (AD) determines the trustworthiness of routing information sources when multiple protocols advertise the same destination prefix.
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.