McAfee Secure

Cisco 300-420 Bundle

Exam Code: 300-420

Exam Name Designing Cisco Enterprise Networks (ENSLD)

Certification Provider: Cisco

Corresponding Certification: CCNP Enterprise

Cisco 300-420 Bundle $25.00
300-420 Sample 1 300-420 Sample 2 300-420 Sample 3 300-420 Sample 4 300-420 Sample 5 300-420 Sample 6 300-420 Sample 7 300-420 Sample 8 300-420 Sample 9 300-420 Sample 10

100% Cisco 300-420 Guaranteed Success With Testking Training Materials

Get Real 300-420 Exam Questions & Expert Verified Answers as Experienced on the Real Exam!

  • Questions & Answers

    300-420 Questions & Answers

    416 Questions & Answers

    The ultimate exam preparation tool, Questions & Answers mirrors the actual 300-420 exam while allowing you to hone and measure every aspect of your test-taking ability.

  • 300-420 Video Course

    300-420 Training Course

    75 Video Lectures

    300-420 Video Course is developed by Cisco Professionals to help you pass the 300-420 exam.

    Description

    This course will improve your knowledge and skills required to pass Designing Cisco Enterprise Networks (ENSLD) exam.

Designing Cisco Enterprise Networks (ENSLD) (300-420) Practice Tests

Satisfaction Guaranteed

Money Back Guarantee

Testking provides hassle-free money back guarantee with our products. That is because we have 100% trust in the abilities of our professional and experience product team, and our record is a proof of that.

99.6% PASS RATE
Total Cost: $164.98
Bundle Price: $139.98

Purchase Individually

  • Questions & Answers

    Questions & Answers

    416 Questions

    $124.99
  • 300-420 Video Course

    Training Course

    75 Video Lectures

    $39.99

Cisco 300-420 Practice Test 32

Question 310

In a technical design review: During a predeployment review for a public-sector campus, the team discovers this design gap: a fiber uplink loses inbound BPDUs while remaining electrically up and starts forwarding in ways that risk a loop. An approval gate requires both a measurable acceptance check and a durable prevention control. Which technical principle BEST explains the design decision?

  1. Ordinary local broadcast frames do not propagate across a Layer 3 boundary without an explicit WoL relay design.
  2. MST can map multiple VLANs to a smaller set of spanning-tree instances while Layer 2 domain size still matters.
  3. Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding.
  4. Per-port support does not guarantee the chassis can supply simultaneous power across all endpoints.

Explanation

Correct Answer

C:

Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. The correct engineering response is: Use Loop Guard where appropriate to stop an expected non-designated port from transitioning to forwarding on lost BPDUs. The observable check is: The suspected port is held loop-inconsistent under the test condition instead of creating a forwarding loop. The public-sector campus acceptance record also captures this result.

Incorrect Answers

A:

Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. The offered choice instead concerns a different principle: Ordinary local broadcast frames do not propagate across a Layer 3 boundary without an explicit WoL relay design. Those technical conditions are not interchangeable.

B:

Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. The offered choice instead concerns a different principle: MST can map multiple VLANs to a smaller set of spanning-tree instances while Layer 2 domain size still matters. Those technical conditions are not interchangeable.

D:

Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. The offered choice instead concerns a different principle: Per-port support does not guarantee the chassis can supply simultaneous power across all endpoints. Those technical conditions are not interchangeable.

Question 311

An engineering reviewer needs objective proof for the following: During a predeployment review for a public-sector campus, the team discovers this design gap: a fiber uplink loses inbound BPDUs while remaining electrically up and starts forwarding in ways that risk a loop. An approval gate requires both a measurable acceptance check and a durable prevention control. Which acceptance observation BEST establishes the intended result?

  1. Forged ARP replies fail validation while legitimate endpoint ARP continues to resolve.
  2. A planned uplink failure recovers within the agreed convergence objective without loops.
  3. All devices boot concurrently without power-denial events and the switch retains measurable headroom.
  4. The suspected port is held loop-inconsistent under the test condition instead of creating a forwarding loop. The public-sector campus acceptance record also captures this result.

Explanation

Correct Answer

D:

The suspected port is held loop-inconsistent under the test condition instead of creating a forwarding loop. The public-sector campus acceptance record also captures this result. Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding.

Incorrect Answers

A:

DAI checks ARP packet bindings to reduce ARP spoofing within the Layer 2 broadcast domain. In the case being tested, Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. The necessary acceptance evidence is: The suspected port is held loop-inconsistent under the test condition instead of creating a forwarding loop. The public-sector campus acceptance record also captures this result.

B:

RSTP enables faster convergence than legacy 802.1D in supported topologies when port roles are correctly configured. In the case being tested, Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. The necessary acceptance evidence is: The suspected port is held loop-inconsistent under the test condition instead of creating a forwarding loop. The public-sector campus acceptance record also captures this result.

C:

Per-port support does not guarantee the chassis can supply simultaneous power across all endpoints. In the case being tested, Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. The necessary acceptance evidence is: The suspected port is held loop-inconsistent under the test condition instead of creating a forwarding loop. The public-sector campus acceptance record also captures this result.

Question 312

The change advisory board sees a repeat risk in this case: During a predeployment review for a public-sector campus, the team discovers this design gap: a fiber uplink loses inbound BPDUs while remaining electrically up and starts forwarding in ways that risk a loop. An approval gate requires both a measurable acceptance check and a durable prevention control. Which preventive design control MOST DIRECTLY addresses this specific risk?

  1. Pair spanning-tree protections with fiber health monitoring and UDLD where supported. Apply the same control to the public-sector campus rollout checklist.
  2. Track PoE class and endpoint growth in access-switch capacity plans.
  3. Review trusted port assignments and rate limits as topology changes.
  4. Standardize EtherChannel negotiation modes and link speed settings on both ends.

Explanation

Correct Answer

A:

Pair spanning-tree protections with fiber health monitoring and UDLD where supported. Apply the same control to the public-sector campus rollout checklist. This control targets the underlying design risk. Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. The follow-up acceptance check remains: The suspected port is held loop-inconsistent under the test condition instead of creating a forwarding loop. The public-sector campus acceptance record also captures this result.

Incorrect Answers

B:

Per-port support does not guarantee the chassis can supply simultaneous power across all endpoints. The repeat risk here is different: Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. A directly relevant preventive control is: Pair spanning-tree protections with fiber health monitoring and UDLD where supported. Apply the same control to the public-sector campus rollout checklist.

C:

DHCP snooping separates trusted DHCP sources from untrusted access ports and can block rogue server messages. The repeat risk here is different: Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. A directly relevant preventive control is: Pair spanning-tree protections with fiber health monitoring and UDLD where supported. Apply the same control to the public-sector campus rollout checklist.

D:

LACP requires peer participation and compatible member parameters before an aggregated bundle can form reliably. The repeat risk here is different: Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. A directly relevant preventive control is: Pair spanning-tree protections with fiber health monitoring and UDLD where supported. Apply the same control to the public-sector campus rollout checklist.

Question 313

A design team must resolve this enterprise network problem: A fiber pair has one-way transmission that is invisible to an ordinary link-up indicator. Which action MOST DIRECTLY meets the stated design requirement?

  1. Calculate aggregate PoE demand including startup spikes and choose switches with adequate supported power budgets.
  2. Enable DHCP snooping and trust only the approved server-facing paths.
  3. Enable supported UDLD protection on critical inter-switch fiber links.
  4. Use an appropriate rapid spanning-tree design with correct edge-port roles and designated forwarding paths.

Explanation

Correct Answer

C:

Enable supported UDLD protection on critical inter-switch fiber links. This action addresses the stated design problem. UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. A practical confirmation is: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode.

Incorrect Answers

A:

Per-port support does not guarantee the chassis can supply simultaneous power across all endpoints. The actual fault is governed by a different mechanism: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The needed response is: Enable supported UDLD protection on critical inter-switch fiber links.

B:

DHCP snooping separates trusted DHCP sources from untrusted access ports and can block rogue server messages. The actual fault is governed by a different mechanism: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The needed response is: Enable supported UDLD protection on critical inter-switch fiber links.

D:

RSTP enables faster convergence than legacy 802.1D in supported topologies when port roles are correctly configured. The actual fault is governed by a different mechanism: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The needed response is: Enable supported UDLD protection on critical inter-switch fiber links.

Question 314

The design record describes this issue: A fiber pair has one-way transmission that is invisible to an ordinary link-up indicator. Which technical principle BEST explains the design decision?

  1. LACP requires peer participation and compatible member parameters before an aggregated bundle can form reliably.
  2. DHCP snooping separates trusted DHCP sources from untrusted access ports and can block rogue server messages.
  3. BPDU Guard protects an edge port from participating in an unintended bridge topology when BPDUs appear.
  4. UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses.

Explanation

Correct Answer

D:

UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The correct engineering response is: Enable supported UDLD protection on critical inter-switch fiber links. The observable check is: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode.

Incorrect Answers

A:

UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The offered choice instead concerns a different principle: LACP requires peer participation and compatible member parameters before an aggregated bundle can form reliably. Those technical conditions are not interchangeable.

B:

UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The offered choice instead concerns a different principle: DHCP snooping separates trusted DHCP sources from untrusted access ports and can block rogue server messages. Those technical conditions are not interchangeable.

C:

UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The offered choice instead concerns a different principle: BPDU Guard protects an edge port from participating in an unintended bridge topology when BPDUs appear. Those technical conditions are not interchangeable.

Question 315

After designing a change for the following scenario: A fiber pair has one-way transmission that is invisible to an ordinary link-up indicator. Which acceptance observation BEST establishes the intended result?

  1. A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode.
  2. A planned uplink failure recovers within the agreed convergence objective without loops.
  3. All devices boot concurrently without power-denial events and the switch retains measurable headroom.
  4. A test BPDU on the access port triggers the expected protective state while legitimate uplinks stay operational.

Explanation

Correct Answer

A:

A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode. UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses.

Incorrect Answers

B:

RSTP enables faster convergence than legacy 802.1D in supported topologies when port roles are correctly configured. In the case being tested, UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The necessary acceptance evidence is: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode.

C:

Per-port support does not guarantee the chassis can supply simultaneous power across all endpoints. In the case being tested, UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The necessary acceptance evidence is: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode.

D:

BPDU Guard protects an edge port from participating in an unintended bridge topology when BPDUs appear. In the case being tested, UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The necessary acceptance evidence is: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode.

Question 316

A preventive architecture review covers this situation: A fiber pair has one-way transmission that is invisible to an ordinary link-up indicator. Which preventive design control MOST DIRECTLY addresses this specific risk?

  1. Track PoE class and endpoint growth in access-switch capacity plans.
  2. Audit optical connections and align UDLD mode on critical peer links.
  3. Document intended spanning-tree root placement and root-guard boundary ports.
  4. Review trusted port assignments and rate limits as topology changes.

Explanation

Correct Answer

B:

Audit optical connections and align UDLD mode on critical peer links. This control targets the underlying design risk. UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The follow-up acceptance check remains: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode.

Incorrect Answers

A:

Per-port support does not guarantee the chassis can supply simultaneous power across all endpoints. The repeat risk here is different: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. A directly relevant preventive control is: Audit optical connections and align UDLD mode on critical peer links.

C:

Root Guard prevents a designated switch port from accepting a downstream superior-root claim. The repeat risk here is different: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. A directly relevant preventive control is: Audit optical connections and align UDLD mode on critical peer links.

D:

DHCP snooping separates trusted DHCP sources from untrusted access ports and can block rogue server messages. The repeat risk here is different: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. A directly relevant preventive control is: Audit optical connections and align UDLD mode on critical peer links.

Question 317

A new campus or WAN review presents this constraint: During a predeployment review for a large research campus, the team discovers this design gap: a fiber pair has one-way transmission that is invisible to an ordinary link-up indicator. An approval gate requires both a measurable acceptance check and a durable prevention control. Which action MOST DIRECTLY meets the stated design requirement?

  1. Use Root Guard on the port where superior BPDUs must not be accepted.
  2. Use Loop Guard where appropriate to stop an expected non-designated port from transitioning to forwarding on lost BPDUs.
  3. Apply Dynamic ARP Inspection where supported using valid DHCP snooping bindings or other authorized ARP entries.
  4. Enable supported UDLD protection on critical inter-switch fiber links.

Explanation

Correct Answer

D:

Enable supported UDLD protection on critical inter-switch fiber links. This action addresses the stated design problem. UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. A practical confirmation is: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode. The large research campus acceptance record also captures this result.

Incorrect Answers

A:

Root Guard prevents a designated switch port from accepting a downstream superior-root claim. The actual fault is governed by a different mechanism: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The needed response is: Enable supported UDLD protection on critical inter-switch fiber links.

B:

Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. The actual fault is governed by a different mechanism: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The needed response is: Enable supported UDLD protection on critical inter-switch fiber links.

C:

DAI checks ARP packet bindings to reduce ARP spoofing within the Layer 2 broadcast domain. The actual fault is governed by a different mechanism: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The needed response is: Enable supported UDLD protection on critical inter-switch fiber links.

Question 318

For this Cisco ENSLD design case: During a predeployment review for a large research campus, the team discovers this design gap: a fiber pair has one-way transmission that is invisible to an ordinary link-up indicator. An approval gate requires both a measurable acceptance check and a durable prevention control. Which technical principle BEST explains the design decision?

  1. UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses.
  2. Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding.
  3. RSTP enables faster convergence than legacy 802.1D in supported topologies when port roles are correctly configured.
  4. DHCP snooping separates trusted DHCP sources from untrusted access ports and can block rogue server messages.

Explanation

Correct Answer

A:

UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The correct engineering response is: Enable supported UDLD protection on critical inter-switch fiber links. The observable check is: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode. The large research campus acceptance record also captures this result.

Incorrect Answers

B:

UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The offered choice instead concerns a different principle: Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. Those technical conditions are not interchangeable.

C:

UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The offered choice instead concerns a different principle: RSTP enables faster convergence than legacy 802.1D in supported topologies when port roles are correctly configured. Those technical conditions are not interchangeable.

D:

UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The offered choice instead concerns a different principle: DHCP snooping separates trusted DHCP sources from untrusted access ports and can block rogue server messages. Those technical conditions are not interchangeable.

Question 319

During acceptance testing for this network design: During a predeployment review for a large research campus, the team discovers this design gap: a fiber pair has one-way transmission that is invisible to an ordinary link-up indicator. An approval gate requires both a measurable acceptance check and a durable prevention control. Which acceptance observation BEST establishes the intended result?

  1. All devices boot concurrently without power-denial events and the switch retains measurable headroom.
  2. A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode. The large research campus acceptance record also captures this result.
  3. The suspected port is held loop-inconsistent under the test condition instead of creating a forwarding loop.
  4. Forged ARP replies fail validation while legitimate endpoint ARP continues to resolve.

Explanation

Correct Answer

B:

A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode. The large research campus acceptance record also captures this result. UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses.

Incorrect Answers

A:

Per-port support does not guarantee the chassis can supply simultaneous power across all endpoints. In the case being tested, UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The necessary acceptance evidence is: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode. The large research campus acceptance record also captures this result.

C:

Loop Guard helps protect against unidirectional BPDU loss causing unexpected spanning-tree forwarding. In the case being tested, UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The necessary acceptance evidence is: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode. The large research campus acceptance record also captures this result.

D:

DAI checks ARP packet bindings to reduce ARP spoofing within the Layer 2 broadcast domain. In the case being tested, UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The necessary acceptance evidence is: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode. The large research campus acceptance record also captures this result.

Question 320

Operations wants to avoid recurrence of this design flaw: During a predeployment review for a large research campus, the team discovers this design gap: a fiber pair has one-way transmission that is invisible to an ordinary link-up indicator. An approval gate requires both a measurable acceptance check and a durable prevention control. Which preventive design control MOST DIRECTLY addresses this specific risk?

  1. Document intended spanning-tree root placement and root-guard boundary ports.
  2. Maintain binding consistency for statically addressed devices and trusted uplinks.
  3. Audit optical connections and align UDLD mode on critical peer links. Apply the same control to the large research campus rollout checklist.
  4. Treat only verified host-facing interfaces as BPDU Guard edge ports.

Explanation

Correct Answer

C:

Audit optical connections and align UDLD mode on critical peer links. Apply the same control to the large research campus rollout checklist. This control targets the underlying design risk. UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. The follow-up acceptance check remains: A simulated unidirectional failure raises a UDLD event and the protection action matches the approved mode. The large research campus acceptance record also captures this result.

Incorrect Answers

A:

Root Guard prevents a designated switch port from accepting a downstream superior-root claim. The repeat risk here is different: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. A directly relevant preventive control is: Audit optical connections and align UDLD mode on critical peer links. Apply the same control to the large research campus rollout checklist.

B:

DAI checks ARP packet bindings to reduce ARP spoofing within the Layer 2 broadcast domain. The repeat risk here is different: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. A directly relevant preventive control is: Audit optical connections and align UDLD mode on critical peer links. Apply the same control to the large research campus rollout checklist.

D:

BPDU Guard protects an edge port from participating in an unintended bridge topology when BPDUs appear. The repeat risk here is different: UDLD can detect certain unidirectional Layer 2 link conditions that simple physical carrier status misses. A directly relevant preventive control is: Audit optical connections and align UDLD mode on critical peer links. Apply the same control to the large research campus rollout checklist.