Question 1,052 of 2,015
VRF and Path IsolationeasyMultiple ChoiceObjective-mapped

Quick Answer

The answer is the Multi-Exit Discriminator (MED) attribute, which is preferred when it has the lowest value. This is because the MED is a metric used to influence inbound traffic from a neighboring autonomous system (AS); a lower MED value signals to that neighbor that this path is more preferred for entering your AS, making it the decisive factor in path selection when multiple entry points exist. On the ENCOR 350-401 exam, this concept tests your understanding of BGP path selection and how MED differs from weight or local preference—common traps include confusing MED with local preference (which prefers the highest value) or forgetting that MED is only compared between paths from the same neighboring AS. To remember, think of MED as the “entrance fee” you want to be low: the lower the MED, the more attractive the door into your network.

350-401 VRF and Path Isolation Practice Question

This 350-401 practice question tests your understanding of vrf and path isolation. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. 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 BGP attribute is preferred when it has the lowest value?

Question 1easymultiple choice
Open the full BGP breakdown →

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

MED (Multi-Exit Discriminator)

The Multi-Exit Discriminator (MED) is a BGP attribute used to influence inbound traffic from a neighboring AS. A lower MED value is preferred because it indicates a more preferred path into the AS, making it the correct answer when the question asks for the attribute preferred with the lowest value.

Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • MED (Multi-Exit Discriminator)

    Why this is correct

    Correct. Lower MED is preferred.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Local Preference

    Why it's wrong here

    Incorrect. Higher Local Preference is preferred.

  • Weight

    Why it's wrong here

    Incorrect. Higher Weight is preferred.

  • AS Path

    Why it's wrong here

    Incorrect. Shorter AS Path is preferred, not lower value.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Cisco often tests the confusion between attributes that prefer the lowest value (MED) versus those that prefer the highest value (Weight, Local Preference), and candidates mistakenly apply the 'lowest is best' rule to all attributes without remembering the specific behavior of each.

Detailed technical explanation

How to think about this question

MED is exchanged between eBGP peers and is typically used in multi-homed scenarios to influence which link an external AS uses to reach the local AS. Under the hood, MED is a 4-byte unsigned integer (RFC 4271) that is compared only when paths come from the same neighboring AS (or same AS set when bgp bestpath med missing-as-worst is configured). In real-world deployments, MED values are often set to reflect IGP metrics or link bandwidth to optimize inbound traffic engineering.

KKey Concepts to Remember

  • Read the scenario before looking for a memorised answer.
  • Find the constraint that changes the correct option.
  • Eliminate answers that are true in general but not in this case.

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

Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

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.

What to study next

Got this wrong? Here's your next step.

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FAQ

Questions learners often ask

What does this 350-401 question test?

VRF and Path Isolation — This question tests VRF and Path Isolation — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: MED (Multi-Exit Discriminator) — The Multi-Exit Discriminator (MED) is a BGP attribute used to influence inbound traffic from a neighboring AS. A lower MED value is preferred because it indicates a more preferred path into the AS, making it the correct answer when the question asks for the attribute preferred with the lowest value.

What should I do if I get this 350-401 question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Last reviewed: Jun 24, 2026

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This 350-401 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 350-401 exam.