3.1.1.5 Packet Tracer – Examining a Redundant Design

3.1.1.5 Packet Tracer – Examining a Redundant Design

From year to year, Cisco has updated many versions with difference questions. The latest version is version 6.0 in 2018. What is your version? It depends on your instructor creating your class. We recommend you to go thought all version if you are not clear. While you take online test with netacad.com, You may get random questions from all version. Each version have 1 to 10 different questions or more. After you review all questions, You should practice with our online test system by go to "Online Test" link below.

Version 5.02Version 5.03Version 6.0Online Assessment
Chapter 3 ExamChapter 3 ExamChapter 3 ExamOnline Test
Next Chapter
Chapter 4 ExamChapter 4 ExamChapter 4 ExamOnline Test
Lab Activities
3.1.1.5 Packet Tracer – Examining a Redundant Design
3.3.1.5 Packet Tracer – Configuring PVST
3.3.2.2 Packet Tracer – Configuring Rapid PVST

Packet Tracer – Examining a Redundant Design (Answer Version)

Answer Note: Red font color or Gray highlights indicate text that appears in the Answer copy only.

Topology

3.1.1.5 Packet Tracer – Examining a Redundant Design

3.1.1.5 Packet Tracer – Examining a Redundant Design

Objectives

Part 1: Check for STP Convergence

Part 2: Examine the ARP Process

Part 3: Test Redundancy in a Switched Network

Background

In this activity, you will observe how STP operates, by default, and how it reacts when faults occur. Switches have been added to the network “out of the box”. Cisco switches can be connected to a network without any additional action required by the network administrator. For the purpose of this activity, the bridge priority was modified.

Part 1: Check for STP Convergence

When STP is fully converged, the following conditions exist:

  • All PCs have green link lights on the switched ports.
  • Access layer switches have one forwarding uplink (green link) to a distribution layer switch and a blocking uplink (amber link) to a second distribution layer switch.
  • Distribution layer switches have one forwarding uplink (green link) to a core layer switch and a blocking uplink (amber link) to another core layer switch.

Part 2: Examine the ARP Process

Step 1: Switch to Simulation mode.

Step 2: Ping from PC1 to PC6.

  1. Use the Add Simple PDU tool to create a PDU from PC1 to PC6. Verify that ARP and ICMP are selected in the Event List Filters. Click Capture/Forward to examine the ARP process as the switched network learns the MAC addresses of PC1 and PC6. Notice that all possible loops are stopped by blocking ports. For example, the ARP request from PC1 travels from A1 to D2 to C1 to D1 and then back to A1. However, because STP is blocking the link between A1 and D1, no loop occurs.
  2. Notice that the ARP reply from PC6 travels back along one path. Why? It is the only valid path when STP is blocking the redundant links.
  3. Record the loop-free path between PC1 and PC6. PC1 > A1 > D2 > C1 > D3 > A6 > PC6

Step 3: Examine the ARP process again.

  1. Below the Scenario 0 drop-down list, click New to create Scenario 1. Examine the ARP process again by pinging between two different PCs.
  2. What part of the path changed from the last set of pings? Answers may vary depending on which PC students ping from.

Part 3: Test Redundancy in a Switched Network

Step 1: Delete the link between A1 and D2.

Switch to Realtime mode. Delete the link between A1 and D2. It takes some time for STP to converge and establish a new, loop-free path. Because only A1 is affected, watch for the amber light on the link between A1 and D1 to change to green. You can click Fast Forward Time to accelerate the STP convergence process.

Step 2: Ping between PC1 and PC6.

  1. After the link between A1 and D1 is active (indicated by a green light), switch to Simulation mode and create Scenario 2. Ping between PC1 and PC6 again.
  2. Record the new loop-free path. PC1 > A1 > D1 > C1 > D3 > A6 > PC6

Step 3: Delete link between C1 and D3.

  1. Switch to Realtime mode. Notice that the links between D3 and D4 to C2 are amber. Delete the link between C1 and D3. It takes some time for STP to converge and establish a new, loop-free path. Watch the amber links on D3 and D4. You can click Fast Forward Time to accelerate the STP convergence process.
  2. Which link is now the active link to C2? Link between D3 F0/1 to C2 F0/2

Step 4: Ping between PC1 and PC6.

  1. Switch to Simulation mode and create Scenario 3. Ping between PC1 and PC6.
  2. Record the new loop-free path. PC1 > A1 > D1 > C1 > D4 > A6 > PC6

Step 5: Delete D4.

Switch to Realtime mode. Notice that A4, A5, and A6 are all forwarding traffic to D4. Delete D4. It takes some time for STP to converge and establish a new, loop-free path. Watch for the links between A4, A5, and A6 to D3 transition to forwarding (green). All three switches should now be forwarding to D3.

Step 6: Ping between PC1 and PC6.

  1. Switch to Simulation mode and create Scenario 4. Ping between PC1 and PC6.
  2. Record the new loop-free path. PC1 > A1 > D1 > C1 > C2 > D3 > A6 > PC6
  3. What is unique about the new path that you have not seen before? D3 is now the designated switch for packet forwarding if PC1 would like to ping PC6, no redundant path below C2.

Step 7: Delete C1.

Switch to Realtime mode. Notice that D1 and D2 are both forwarding traffic to C1. Delete C1. It takes some time for STP to converge and establish a new, loop-free path. Watch for the links between D1 and D2 to C2 to transition to forwarding (green). Once converged, both switches should now be forwarding to C2.

Step 8: Ping between PC1 and PC6.

  1. Switch to Simulation mode and create Scenario 5. Ping between PC1 and PC6.
  2. Record the new loop-free path. PC1 > A1 > D1 > C2 > D3 > A6 > PC6

Suggested Scoring Rubric

Activity SectionQuestion LocationPossible PointsEarned Points
Part 2: Examine the ARP ProcessStep 2b5
Step 2c15
Step 35
Part 2 Total25
Part 3: Test Redundancy in a Switched NetworkStep 215
Step 35
Step 415
Step 6b15
Step 6c10
Step 815
Part 3 Total75
Total Score100

From year to year, Cisco has updated many versions with difference questions. The latest version is version 6.0 in 2018. What is your version? It depends on your instructor creating your class. We recommend you to go thought all version if you are not clear. While you take online test with netacad.com, You may get random questions from all version. Each version have 1 to 10 different questions or more. After you review all questions, You should practice with our online test system by go to "Online Test" link below.

Version 5.02Version 5.03Version 6.0Online Assessment
Chapter 3 ExamChapter 3 ExamChapter 3 ExamOnline Test
Next Chapter
Chapter 4 ExamChapter 4 ExamChapter 4 ExamOnline Test
Lab Activities
3.1.1.5 Packet Tracer – Examining a Redundant Design
3.3.1.5 Packet Tracer – Configuring PVST
3.3.2.2 Packet Tracer – Configuring Rapid PVST