Multi-Router LAN with Wireless Integration and Port Security: Challenges and Solutions | IT Services, Cybersecurity & Networking Solutions

Introduction

In this blog, we explore the Multi-Router LAN with Wireless Integration and Port Security Simulation created in Cisco Packet Tracer.
The simulation demonstrates secure multi-router LAN segmentation, wireless access, and rogue device mitigation while aligning with OSI and TCP/IP models.

This project is particularly relevant for network engineers, DevNet learners, and cybersecurity enthusiasts, showing how to apply practical network security strategies in a multi-department environment.

Network Topology

Network Topology
The topology demonstrates 3 routers, 3 switches, multiple PCs, and wireless integration.

Simulation Overview

Key Features Implemented

RIP Routing: Dynamic routing between all LAN segments
Wireless Integration: WPA2-PSK and MAC filtering for legitimate laptops
Port Security: Enabled on switch access ports, maximum MAC addresses, violation modes
Rogue Device Mitigation: Unauthorized devices blocked automatically
LAN Segmentation: Departments logically isolated but interconnected

Devices Used

3 Routers, 3 Switches, 3 PCs
2 Wireless Routers / Access Points
2 Laptops: Legitimate and Rogue

Challenges and Resolutions

1. Port Security Violations on Wireless Router Uplink

Challenge: Wireless router uplink port kept entering violation due to multiple MAC addresses from wireless clients.
Resolution: Increased allowed MAC addresses to 2, set violation mode to restrict. Legitimate devices could connect while rogue devices were blocked.

2. Rogue Laptop Access Denial

Challenge: Rogue laptop appeared in MAC address table despite being unauthorized.
Resolution: Verified using show port-security address and confirmed ping tests. Rogue device failed connectivity; violation counts increased correctly.

3. Wireless Router Configuration Limitations in Packet Tracer

Challenge: Packet Tracer APs don’t support WPA2 or MAC filtering.
Resolution: Replaced with real home wireless router (Linksys WRT300N) configured with WPA2, MAC filtering, and static IPs.

4. Connecting Legitimate Wireless Devices

Challenge: Legitimate wireless device failed connectivity initially.
Resolution: Corrected WPA2 password and default gateway. Device communicated successfully with router and LAN.