Wire Your First Virtual LAN

Build and troubleshoot a virtual switched LAN with Cisco Packet Tracer.

Introduction

30 Second Summary

A cable can look connected while two computers still fail to exchange a single message. The real skill is knowing whether the fault lives in the link or the addresses.

In this project, you will build a two-computer local area network in Cisco Packet Tracer. You will diagnose a deliberate IPv4 addressing fault.

What You'll Build

You will watch a successful ping travel between two named PCs through a switch.

By the end of this project, you'll have:

  • A working two-PC LAN with green link indicators. You can trace each Ethernet cable to its switch port. Each PC's IPv4 address is ready to inspect. The subnet mask is visible beside it.
  • A repeatable troubleshooting demo that reproduces a failed ping while both cables stay active. You can repair the addressing mismatch. Successful replies prove two-way communication.
  • A packet animation showing how ARP discovers a hardware address before ICMP tests connectivity. A saved project-1-virtual-lan.pkt file keeps the demonstration ready for Project 2.
  • Secret Mission: Add and verify a third office PC without copying a completed configuration.

Are there any prerequisites?

No networking experience or physical equipment is required. The guide walks you through the Cisco Networking Academy account before installing Cisco Packet Tracer on Windows.

Before We Start

This first checkpoint locks in your goal before you touch the simulator. You will build a two-PC virtual Ethernet LAN through a switch, then test its physical cabling and IPv4 addressing because green link indicators alone do not prove end-to-end connectivity.

Set Up Cisco Packet Tracer

Your two-PC office LAN needs a safe lab where each connection produces visible evidence. Cisco Packet Tracer gives you that lab on your Windows computer without requiring physical networking equipment.

A free Cisco Networking Academy account unlocks the course path. The complimentary Getting Started with Cisco Packet Tracer course provides official access to the current Windows installer.

In this step, get ready to:
  • Gain course access through a free Cisco Networking Academy account.
  • Install the current Cisco Packet Tracer Windows application.
  • Authenticate Cisco Packet Tracer to reach a blank logical workspace.
Create your Cisco Networking Academy account

Cisco Networking Academy provides the complimentary course that unlocks Packet Tracer access. Your enrollment connects the account to the official software download path.

Why Use a Virtual Lab?

A physical lab requires computers, switches, and Ethernet cables. A network simulator places the same device roles inside one application.

The workflow still follows the same sequence from cabling to traffic testing.

  • Visit Cisco's Packet Tracer enrollment guidance.
  • Follow the course link for Getting Started with Cisco Packet Tracer.
  • Create a free Cisco Networking Academy account if you are new to the platform.
  • Sign in with your existing Cisco Networking Academy account if you already have one.
  • Enroll in the complimentary Getting Started with Cisco Packet Tracer course.
  • Confirm that you can access the course content.

Good progress. Your Cisco Networking Academy account now has the course access needed to download Packet Tracer.

Install Cisco Packet Tracer on Windows

Cisco keeps the current installer in its Resource Hub. This live download path avoids relying on a version that may become outdated.

What Will the Installer Ask?

The setup wizard begins with the license agreement. It then moves through the destination, Start Menu, additional tasks, and installation review pages.

The choices below follow Cisco's official Windows setup sequence.

  • Select the downloaded installer from your browser's downloads panel.
  • Select I accept the agreement on the license agreement screen.
  • Continue through Select Destination Location.
  • Continue through Select Start Menu Folder.
  • Continue through Select Additional Tasks.
  • Continue from Ready to Install.
  • Select Install.
  • Complete the setup wizard when the installation finishes.

The setup wizard confirms that Cisco Packet Tracer is installed locally.

Installation Did Not Complete?

Confirm that you downloaded the Windows installer from the official Resource Hub. Close any earlier Packet Tracer installer before retrying.

Ask for targeted help with diagnosing the Packet Tracer installation, or compare your steps with Cisco Learning Network Packet Tracer guidance.

  • Press the Windows key to open Windows search.
  • Type Cisco Packet Tracer into Windows search.

You should see Cisco Packet Tracer in the search results. That is the software hurdle cleared: the simulator is installed and ready to launch.

Launch Cisco Packet Tracer

The first launch asks about multi-user mode. Packet Tracer then hands authentication to your browser.

What Happens on First Launch?

The browser handoff can feel like the app disappeared because Cisco completes authentication outside the simulator.

A successful browser message tells you when to return to Packet Tracer.

  • Select Cisco Packet Tracer from the Windows search results.
  • Select No when asked Would you like to run multi-user when the application starts?.
  • Select LOGIN in the Cisco Packet Tracer Login window.
  • Sign in through the browser with your Cisco Networking Academy account.
  • Confirm that the browser displays You have successfully logged in to Cisco Packet Tracer. You may close this tab.

Before you return to the app, what should successful authentication leave ready for you?

  • Return to Cisco Packet Tracer from the Windows taskbar.

You should see a blank logical workspace. This proves that Packet Tracer is installed, authenticated, and ready for your first topology.

Login Did Not Reach the Workspace?

Confirm that the browser displayed the successful login message. Return to the same Packet Tracer window that opened the browser.

Ask for targeted help with diagnosing the Packet Tracer login, or review Cisco Learning Network Packet Tracer guidance.

Your virtual networking lab is ready. Next, you will place two PCs and connect them through a switch.

Build and Wire the LAN

Your browser login brought you back to a blank Cisco Packet Tracer workspace. That canvas is ready to become a small office LAN.

Building the physical layer first prevents later IPv4 settings from hiding a cabling mistake. Green indicators confirm each Ethernet link is active.

In this step, get ready to:
  • Place the two named PC endpoints.
  • Place a 2960 switch between the PCs.
  • Connect each PC to its assigned switch interface with Copper Straight-through cabling.
Build the three-device layout

A switch forwards local Ethernet traffic between connected endpoints. Placing it in the middle makes each cable path easy to trace.

  • Select End Devices in the Device-Type selection area.
  • Select the generic PC in the Device-Specific selection area.
  • Click an open area near the left side of the logical workspace to place the first PC.
  • Click a second open area near the right side of the logical workspace to place the second PC.
  • Choose the 2960 switch from the device selection areas.
  • Click the open area between the PCs to place the switch.
  • Use the first PC's Config tab to rename it PC-A.
  • Use the second PC's Config tab to rename it PC-B.

You should see the labels PC-A and PC-B on opposite sides of one 2960 switch.

Missing a Device or Name?

  • Confirm that both generic PCs came from End Devices.
  • Confirm that the switch model reads 2960.
  • Repeat the rename action from each PC's Config tab if a label is unchanged.

Ask for help with fixing a missing Packet Tracer device or label.

Connect PC-A to the switch

The Copper Straight-through cable is the standard Ethernet medium for a switch-to-PC connection. Each endpoint must use its assigned network interface.

  • Select Connections in the Device-Type selection area.
  • Select Copper Straight-through in the Device-Specific selection area.
  • Click PC-A.
  • Select FastEthernet0.
  • Click the 2960 switch.
  • Select FastEthernet0/1.
  • Wait for the PC-A link to converge.

You should see green link indicators at both ends of the PC-A cable.

PC-A Link Stays Red?

  • Confirm that the PC-A endpoint uses FastEthernet0.
  • Confirm that the switch endpoint uses FastEthernet0/1.
  • Replace the cable with Copper Straight-through if another cable type was used.

Ask for help with diagnosing the PC-A link.

Connect PC-B to the switch
  • Select Connections in the Device-Type selection area.
  • Select Copper Straight-through in the Device-Specific selection area.
  • Click PC-B.
  • Select FastEthernet0.
  • Click the 2960 switch.
  • Select FastEthernet0/2.

Packet Tracer may need a short moment to settle the second link. That delay is the switch completing link convergence.

Before you inspect the finished topology, what link state should correct PC-to-switch cabling produce?

  • Wait for both links to finish converging.
  • Inspect both ends of each PC-to-switch cable.

You have your first network win. Both ends of both cables should show green link indicators.

A Link Is Not Green?

  • Confirm that the PC-B endpoint uses FastEthernet0.
  • Confirm that the PC-B switch endpoint uses FastEthernet0/2.
  • Confirm that the PC-A switch endpoint remains connected to FastEthernet0/1.

Ask for help with diagnosing the unfinished physical link.

Your wired LAN now has a proven physical path. Next, you will assign IPv4 addresses that make this healthy-looking topology fail on purpose.

Create a Planned Addressing Failure

Your Cisco Packet Tracer topology already proves that both Ethernet links are physically active. The next question is whether green indicators can prove that PC-A can reach PC-B.

A green link confirms the physical path. End-to-end communication also depends on compatible IPv4 addressing.

In this step, get ready to:
  • Assign a static IPv4 address to PC-A.
  • Assign a static IPv4 address to PC-B.
  • Test end-to-end connectivity from PC-A.
Configure PC-A with a static address

PC-A needs a stable logical identity for the connectivity test. Its subnet mask defines the boundary of its local network.

  • Select PC-A in the logical workspace.
  • Select the Desktop tab in the device window.
  • Select IP Configuration.
  • Select Static.
  • Enter 192.168.10.10 as the IPv4 address.
  • Enter 255.255.255.0 as the subnet mask.
  • Keep the default gateway field empty.

PC-A's IP Configuration screen should now show 192.168.10.10 with the subnet mask 255.255.255.0. The default gateway should remain blank.

PC-A Values Look Wrong?

  • Return to IP Configuration.
  • Confirm that Static remains selected.
  • Re-enter each value without spaces.

Ask for help with checking PC-A's static IPv4 configuration.

Configure PC-B with a static address

PC-B also needs a stable identity before the test. You will use the same subnet mask with a different IPv4 address.

  • Close the PC-A device window.
  • Select PC-B in the logical workspace.
  • Select the Desktop tab in the device window.
  • Select IP Configuration.
  • Select Static.
  • Enter 192.168.20.20 as the IPv4 address.
  • Enter 255.255.255.0 as the subnet mask.
  • Keep the default gateway field empty.

PC-B's IP Configuration screen should now show 192.168.20.20 with the subnet mask 255.255.255.0. The default gateway should remain blank.

  • Close the PC-B device window.
  • Confirm that both cable ends still display green link indicators.

Both physical links should remain green. The address settings have not changed either cable connection.

A Link Is No Longer Green?

  • Confirm that PC-A still connects through FastEthernet0 to FastEthernet0/1 on the switch.
  • Confirm that PC-B still connects through FastEthernet0 to FastEthernet0/2 on the switch.
  • Confirm that each connection uses a Copper Straight-through cable.

Ask for help with restoring the green Ethernet links.

Test the path from PC-A

The ping test checks whether one endpoint can exchange traffic with another. This test reveals whether the green physical links are enough for the current address settings.

  • Select PC-A in the logical workspace.
  • Select the Desktop tab in the device window.
  • Select Command Prompt.

Before you run the test, do you expect the green links to be enough for the ping?

  • Test PC-B from PC-A by running this command:
ping 192.168.20.20

What Does This Command Do?

  • The ping command sends ICMP echo traffic from PC-A.
  • The destination value points to PC-B at 192.168.20.20.
  • Successful replies would prove that traffic can travel across the complete path.

Your ping does not receive successful replies. Both Ethernet links remain green.

That shortfall is intentional. You have proved that an active physical link does not guarantee end-to-end IPv4 connectivity.

Why Did the Ping Fail?

The mask places PC-A in the local network beginning with 192.168.10. It places PC-B in the local network beginning with 192.168.20.

Traffic between these local networks needs a router. This topology has no router.

It also has no default gateway. The addressing mismatch creates the planned failure.

Ping Receives Replies?

  • Return to PC-A's IP Configuration screen.
  • Confirm that its IPv4 address is 192.168.10.10.
  • Return to PC-B's IP Configuration screen.
  • Confirm that its IPv4 address is 192.168.20.20.

Ask for help with reproducing the planned failed ping.

That is a valuable troubleshooting win: you proved that the cables work while the IPv4 path does not. Next, you will place both PCs in one local network and verify two-way communication.

Repair the IPv4 Addressing

Your Cisco Packet Tracer topology already has green Ethernet links through the switch. The failed ping isolated the remaining fault to IPv4 addressing.

Moving PC-B into PC-A's LAN repairs the addressing obstacle. Both endpoints need the same local network because this topology has no router.

In this step, get ready to:
  • Compare both IPv4 addresses using the 255.255.255.0 subnet mask.
  • Move PC-B into PC-A's 192.168.10.0/24 network.
  • Prove that traffic works in both directions.
Compare the network addresses

The 255.255.255.0 mask makes the first three octets the network portion. Devices can communicate directly through this switch when those octets match.

  • Compare the first three octets of 192.168.10.10 with 192.168.20.20.
  • Classify PC-A as part of 192.168.10.0/24.
  • Classify PC-B as part of 192.168.20.0/24.

The different third octets place the PCs in separate local networks. This topology has no router to carry traffic between them.

Move PC-B onto the same network

Only PC-B's host address needs to change. The working cable connection stays untouched.

  • Return to the logical workspace.
  • Select PC-B.
  • Select the Desktop tab.
  • Select IP Configuration.
  • Keep Static selected.
  • Replace the IP address value with 192.168.10.20.
  • Keep the subnet mask set to 255.255.255.0.
  • Leave the default gateway blank.

You should now see 192.168.10.20 on PC-B. Both cable ends should remain green.

Address Did Not Update?

Confirm that you selected PC-B. PC-A should remain on 192.168.10.10.

Check that Static remains selected before entering the new address.

Ask for help with checking the PC-B IPv4 configuration.

Prove two-way communication

A ping tests whether one endpoint can reach another across the LAN. Testing from each PC proves that communication works in both directions.

  • Close PC-B's device window.
  • Return to PC-A in the logical workspace.
  • Select the Desktop tab.
  • Return to the Command Prompt from earlier.
  • Predict whether PC-A can now reach PC-B.
  • Test the path from PC-A to PC-B by running this command:
ping 192.168.10.20

What Does This Test Prove?

The ping command sends ICMP traffic to PC-B. Successful replies show that PC-A can reach it through the switch.

The first request may time out while ARP learns PC-B's hardware address.

You should receive successful replies from 192.168.10.20.

  • Repeat the same ping test if the first request times out while ARP resolves.

Still Missing Successful Replies?

Confirm that PC-B still shows 192.168.10.20.

Confirm that its subnet mask remains 255.255.255.0.

Ask for help with diagnosing the failed PC-A ping.

  • Close PC-A's device window.
  • Return to PC-B in the logical workspace.
  • Select the Desktop tab.
  • Select Command Prompt.
  • Predict whether the return path from PC-B succeeds.
  • Test the path from PC-B to PC-A by running this command:
ping 192.168.10.10

What Does the Return Test Prove?

This test uses PC-B as the source. Successful replies prove that the repaired LAN carries traffic in the opposite direction.

You should receive successful replies from 192.168.10.10.

Strong work. You repaired the logical fault without touching the working cabling.

Return Ping Still Failing?

Confirm that PC-A still shows 192.168.10.10.

Check that PC-B's command targets 192.168.10.10.

Ask for help with diagnosing the failed return ping.

Your LAN now carries traffic in both directions. Next, you will watch ARP and ICMP traffic cross the switch.

Watch Packets Cross the LAN

Your two-PC LAN now carries successful ping traffic through the switch. The next goal is to make that hidden exchange visible.

Cisco Packet Tracer includes Simulation Mode for slowing packet movement across the topology. Each event becomes something you can follow through the network.

ARP exposes how an IPv4 address becomes a local hardware destination. ICMP exposes the echo test behind the successful ping.

In this step, get ready to:
  • Filter the event list to show ARP and ICMP traffic.
  • Trace a Simple PDU from PC-A to PC-B.
  • Save the demonstrated topology as project-1-virtual-lan.pkt.
Filter the simulated traffic

Simulation Mode records network events in a visible sequence. Filtering that sequence keeps the packet trace focused on address discovery and connectivity testing.

  • Select Simulation Mode in the Cisco Packet Tracer workspace from earlier.

You’ll see the Simulation Panel beside the logical workspace.

  • Select Edit Filters in the Event List.
  • Keep ARP and ICMP visible in the filter list.

The event filters should now include both ARP and ICMP.

What Do These Filters Reveal?

ARP resolves a local IPv4 address to a hardware address. This gives the Ethernet frame a destination on the LAN.

ICMP carries the echo request used by ping. Watching both protocols reveals the preparation followed by the connectivity test.

Cannot See Both Protocols?

  • Return to Edit Filters.
  • Confirm that ARP remains visible.
  • Confirm that ICMP remains visible.

Ask for help with finding the Packet Tracer event filters.

Send a Simple PDU

A Simple PDU creates a graphical connectivity test between two devices. Packet Tracer queues the related protocol events until you start the simulation.

  • Select Add Simple PDU in the workspace toolbar.
  • Select PC-A as the source.

PC-A is now the source for the pending packet test.

  • Select PC-B as the destination.

Before you play the events, which protocol do you expect to appear first?

  • Play the queued events by selecting Auto Capture / Play.

You’ll see ARP and ICMP events travel from PC-A through the 2960 switch to PC-B. There it is: your working LAN now has a visible packet path.

What Just Happened?

ARP discovers the hardware address needed for local Ethernet delivery. ICMP then carries the echo request across the same path.

The switch forwards each event between its connected ports. The animation turns a successful ping into a sequence you can inspect.

Only Seeing ICMP?

PC-A may already have PC-B’s hardware address from the earlier ping. Power cycling the virtual devices clears temporary ARP information.

  • Select Power Cycle Devices.
  • Wait until both Ethernet links return to green.
  • Create the Simple PDU from PC-A to PC-B again.

Ask for help with revealing both packet types.

Capture the final evidence

An ARP table stores the relationship between an IPv4 address and a MAC address. PC-A should now have a learned entry for PC-B.

  • Select PC-A in the logical workspace.
  • Select the Desktop tab.
  • Select Command Prompt.

The command prompt opens inside PC-A.

Before you inspect the table, which PC-B address do you expect PC-A to have learned?

  • Display PC-A’s learned address entries by running this command:
arp -a

What Does This Command Do?

The arp -a command displays the address mappings currently learned by PC-A. Each mapping connects an IPv4 address to a hardware address used for local delivery.

You’ll see a learned entry associated with 192.168.10.20. This connects the visible ARP event to the mapping stored by PC-A.

Cannot See the Learned Entry?

Confirm that the command runs inside PC-A’s Command Prompt. Recreate the Simple PDU if the learned entry has expired.

Ask for help with checking PC-A’s ARP table.

Saving the topology preserves the working addresses and cable connections. The file gives you a reusable version of the demonstrated LAN.

  • Return to the logical workspace from earlier.
  • Select File.
  • Select Save As.

You’ll see the Save As window for the current topology.

Before you complete the save, which filename will make this first virtual LAN easy to identify later?

  • Enter project-1-virtual-lan.pkt in the file name field.
  • Select Save.

You’ll return to the topology in Simulation Mode with ARP and ICMP visible. That’s the full proof captured: your LAN is connected, addressed, observable, and saved.

Topology Did Not Save?

Confirm that the filename ends with .pkt. Choose a local folder where your Windows account can save files.

Ask for help with saving the Packet Tracer topology.

Your saved topology now demonstrates physical links, working IPv4 connectivity, learned ARP information, and ICMP traffic crossing the switch.

Secret mission

Add and Verify a Third PC

Extend the office LAN with a third PC on the next available switch port. Give it an unused address before proving that it can communicate with both original PCs.

Clean Up Your Resources

Clean Up Your Resources

Your three-PC LAN lives entirely on your Windows computer in Cisco Packet Tracer. Its local resources cost $0 to keep.

Resources you used:

  • The current Cisco Packet Tracer Windows installation.
  • The locally saved project-1-virtual-lan.pkt topology file containing the working three-PC LAN.

Your free Cisco Networking Academy account remains available. This cleanup only covers resources stored or running on your computer.

Keep everything running

No action needed. Choose this if you plan to reuse the LAN in the next networking project.

  • Keep Cisco Packet Tracer installed on your Windows computer.
  • Keep project-1-virtual-lan.pkt in its original saved location.
  • Keep your Cisco Networking Academy account available for future Packet Tracer courses.

Your three-PC LAN stays ready to reopen for the next networking project.

Pause - I'll come back to this later

Closing Cisco Packet Tracer frees the memory used by the running application. Your saved topology stays available on disk.

  • Return to Cisco Packet Tracer from earlier.
  • Close Cisco Packet Tracer.

Cisco Packet Tracer is no longer running. The project-1-virtual-lan.pkt file remains in its original saved location.

Delete - I don't want to use this again

This option removes the saved topology plus Cisco Packet Tracer from your computer. Removing the topology means you cannot reopen this exact three-PC LAN.

  • Close Cisco Packet Tracer if it is still running.
  • Press the Windows key to open search.
  • Search for project-1-virtual-lan.pkt.
  • Open the folder containing the matching file.
  • Select project-1-virtual-lan.pkt.
  • Delete the selected file.
  • Open Recycle Bin from the Windows desktop.
  • Remove project-1-virtual-lan.pkt permanently.

The topology file no longer appears in its original folder or the Recycle Bin.

  • Press the Windows key to open search.
  • Search for Windows Settings.
  • Open Windows Settings.
  • Select the area that manages installed applications.
  • Find Cisco Packet Tracer in the installed applications list.
  • Select the uninstall control for Cisco Packet Tracer.
  • Follow the confirmation prompts until removal finishes.
  • Search for Cisco Packet Tracer from the Windows search bar.

You should no longer see Cisco Packet Tracer as an installed application.

Nice Work!

Nice Work!

You did it. Your saved Cisco Packet Tracer workspace now contains a working three-PC virtual LAN.

You've learned how to:

  • Build a labeled switched network with the correct Copper Straight-through cabling across active Ethernet links.
  • Use structured troubleshooting to reproduce a failed ping across mismatched IPv4 networks. Repair the subnet mismatch to restore two-way communication.
  • Demonstrate packet simulation by watching ARP discovery precede ICMP traffic. Save the working topology as project-1-virtual-lan.pkt.
  • Secret Mission: Extend the LAN with PC-C on switch port FastEthernet0/3. Prove the new PC reaches both original PCs through successful pings plus a Simple PDU.

Ready to quiz yourself?