Compare star, daisy-chain, and ring failure paths

Compare reachability in three switched topologies before and after one controlled link failure in each.

Packet Pete, your practice guide

Packet Pete
Predict the reading, then compare it with the measurement.

Cisco Packet Tracer

Desktop lab

Compare reachability in three switched topologies before and after one controlled link failure in each.

Tier 3 · Install required · Cisco account required

Version tested: Cisco Packet Tracer 9.0.1 on Ubuntu 22.04 (Apptainer/Xvfb); project saved and execution captured 2026-09-10. Date: 2026-09-10.

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Steps

Screens captured against Cisco Packet Tracer Cisco Packet Tracer 9.0.1 on Ubuntu 22.04 (Apptainer/Xvfb); project saved and execution captured 2026-09-10 on 2026-09-10; the tool may have moved on — the text steps are the contract.

  1. Step 1

    Do
    Open lab.pkt and identify the three labelled topology groups.
    You will see
    PT displays a one-switch star, a three-switch bus-like daisy chain, and a four-switch ring.
    Why it matters
    Keeping the experiments side by side makes the changed link the independent variable.

  2. Step 2

    Do
    Run the saved endpoint ping in the intact star group from Star-PC-A.
    You will see
    The star baseline prints “Sent = 4, Received = 4, Lost = 0 (0% loss)”.
    Why it matters
    The baseline confirms that a later loss is caused by the intervention.

  3. Step 3

    Do
    Remove Star-PC-A’s access link and repeat its endpoint ping.
    You will see
    Star prints “Received = 0, Lost = 4 (100% loss)”.
    Why it matters
    A host with one access link has no alternate path, regardless of the core shape.

  4. Step 4

    Do
    Restore the star link, remove the middle daisy-chain link, and repeat the daisy endpoint ping.
    You will see
    Daisy prints “Received = 0, Lost = 4 (100% loss)”.
    Why it matters
    A serial chain partitions when its only middle path is cut, while startup effects must remain visible.

  5. Step 5

    Do
    Restore the daisy link, remove one inter-switch link in the ring, wait for convergence, and repeat the ring ping.
    You will see
    Ring prints “Received = 4, Lost = 0 (0% loss)” on both visible runs.
    Why it matters
    The ring retains an alternate switched path after one inter-switch failure.

  6. Step 6

    Do
    Inspect the surviving ring path and its port states.
    You will see
    The endpoint Command Prompt remains 4/4 with one inter-switch link absent behind the window.
    Why it matters
    Survival is supported by delivery evidence, not by a topology label alone.

  7. Step 7

    Do
    Restore every link, rerun the star baseline, and save.
    You will see
    The restored star baseline prints 4 sent, 4 received, 0 lost.
    Why it matters
    Restoring the control state makes the comparison reproducible.

Chapter checks

These questions refer to the chapter’s examples. Use the return links to review their answers.

  1. A team selected a wireless protocol before documenting battery limits, message frequency, gateway placement, or addressing. What is the best design response?

    Return to the chapter’s knowledge check

  2. Which evidence gap should block release of an IoT network design?

    Return to the chapter’s knowledge check

Return to Five Considerations for IoT Network Design and Implementation · Browse Labs