LAB OBJECTIVES

By the end of this lab, the student will be able to:

• Verify switch port status using Cisco IOS commands
• Identify Layer 1, Layer 2, and Layer 3 symptoms related to switch connectivity
• Troubleshoot copper and fiber-style media issues using interface statistics
• Detect duplex and speed mismatches on Ethernet links
• Restore end-to-end connectivity by correcting intentional switch port and media faults

DEVICE DETAILS

Device	Role
R1	Edge Router
SW1	Access Switch
SW2	Distribution Switch
Host-A	User PC
Host-B	User PC
SRV-1	Internal Server

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NETWORK TOPOLOGY

Device A	Interface	Device B	Interface	Cable Type
Host-A	Fa0	SW1	Fa0/6	Copper Straight-Through
SW1	Fa0/1	SW2	Fa0/1	Copper Crossover
Host-B	Fa0	SW2	Fa0/2	Copper Straight-Through
SRV-1	Fa0	SW2	Fa0/3	Copper Straight-Through
SW2	G0/1	R1	G0/0	Copper Straight-Through

Topology notes

• SW1 and SW2 are connected through an Ethernet uplink.
• Host-A is attached to SW1.
• Host-B and STV-1 are attached to SW2.
• R1 provides Layer 3 gateway services for VLAN 10 and management reachability.

TOPOLOGY DIAGRAM

IP ADDRESSING TABLE

Device	Interface	IP Address	Subnet Mask	Default Gateway
R1	G0/0.10	192.168.10.1	255.255.255.0	N/A
R1	G0/0.99	192.168.99.1	255.255.255.0	N/A
SW1	VLAN 99	192.168.99.11	255.255.255.0	192.168.99.1
SW2	VLAN 99	192.168.99.12	255.255.255.0	192.168.99.1
Host-A	NIC	192.168.10.10	255.255.255.0	192.168.10.1
Host-B	NIC	192.168.10.20	255.255.255.0	192.168.10.1
Server-1	NIC	192.168.10.100	255.255.255.0	192.168.10.1

VLAN plan

VLAN	Name	Purpose
10	USERS	End devices
99	MGMT	Switch management

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CCNA-STYLE TROUBLESHOOTING CHALLENGE

Troubleshooting Switch Port and Media Problems

Cisco Packet Tracer Simulation

Download the Lab File

This lab was created in Cisco Packet Tracer.

Download .PKT File

Requirements

• Cisco Packet Tracer installed
• Download the .pkt file
• Open the file in Packet Tracer

Troubleshooting Scenario

You have been assigned to investigate user complaints in a small office network.

The following symptoms are reported:

• Host-A (192.168.10.10) cannot reliably reach Host-B (192.168.10.20)
• Host-B 192.168.10.20) cannot reach SRV1-1 (192.168.10.100)
• The administrator cannot always reach SW2 using its management IP (192.168.99.12)
• At times, the uplink between switches appears active, but performance is poor

Your task is to identify and correct the problems using a structured troubleshooting approach.

Requirements

⚠️ Do not erase the configurations and start over. ⚠️

You must investigate and repair the network using normal CCNA troubleshooting logic.

Suggested troubleshooting workflow

1. Identify whether the failure is Layer 1, Layer 2, or Layer 3
2. Check interface status first
3. Review duplex and speed values on both ends of uplinks
4. Inspect VLAN membership and trunk operation
5. Verify management addressing and default gateway settings
6. Test reachability after each correction
7. Save the corrected configuration

Commands you should use

show ip interface brief
show interfaces
show interfaces fastEthernet0/1
show interfaces fastEthernet0/2
show interfaces trunk
show vlan brief
show running-config
ping
traceroute
show mac address-table

Your goals

• Restore connectivity between Host-A and Host-B
• Restore connectivity between Host-B and SRV-1
• Restore management reachability to SW2
• Eliminate the switch uplink performance problem
• Save the working configuration

Final correct state summary

You’re successful when:

• SW2 Fa0/2 is enabled
• SW1 and SW2 uplink duplex/speed settings match
• Host-B is in VLAN 10
• SW2 default gateway is 192.168.99.1
• SW2 Gi0/1 trunk allows VLANs 10 and 99
• Host-A, Host-B, SRV-1, SW1, SW2, and R1 can all communicate as expected

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This lab is designed to practice the exact concepts from your material:

• OSI-based troubleshooting
• copper media symptoms
• CRC/collision interpretation
• duplex and speed mismatch detection
• switch port shutdown recovery
• management IP troubleshooting
• structured CCNA-style troubleshooting logic

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