Router + Switch Integration in Cisco Packet Tracer

 

Router + Switch Integration in Cisco Packet Tracer (Step-by-Step Practical Guide)

If you want to move beyond basic LAN setups, integrating a router with multiple switches is a crucial skill. In this lab, we connect two different networks using a router and enable communication between them using Cisco Packet Tracer.

📌 Lab Overview

This practical demonstrates:

• Two separate LANs
• Each LAN connected to a switch
• Both switches connected to a central router
• Inter-network communication using routing

🧪 Network Topology (From Your Setup)

🔹 LAN 1

Network: 10.0.0.0/8

Devices:

• PC0 → 10.0.0.1
• PC1 → 10.0.0.2
• PC2 → 10.0.0.3

Connected to Switch0

🔹 LAN 2

Network: 192.168.1.0/24

Devices:

• PC3 → 192.168.1.1
• PC4 → 192.168.1.2
• PC5 → 192.168.1.3

Connected to another switch

🔹 Router Configuration

Router (2911) interfaces:

• G0/0 → 10.0.0.4
• G0/1 → 192.168.1.4

👉 This router acts as a gateway between both LANs

🎯 Objective

• Enable communication between LAN1 and LAN2
• Configure router interfaces
• Set default gateways on PCs
• Verify connectivity using ping

🛠️ Step 1: Configure Router Interfaces

Click router → CLI and run:

enable
configure terminal

interface gigabitEthernet 0/0
ip address 10.0.0.4 255.0.0.0
no shutdown

interface gigabitEthernet 0/1
ip address 192.168.1.4 255.255.255.0
no shutdown

end

👉 This activates both interfaces

🌐 Step 2: Configure Default Gateway on PCs

This is the most important step for inter-network communication.

🔹 LAN 1 PCs

Default Gateway → 10.0.0.4

🔹 LAN 2 PCs

Default Gateway → 192.168.1.4

📍 Path:

PC → Desktop → IP Configuration

🔌 Step 3: Verify IP Addressing

Make sure:

• All PCs in LAN1 use 10.0.0.x
• All PCs in LAN2 use 192.168.1.x
• Subnet masks are correct

📡 Step 4: Test Connectivity

🔹 Same Network Test

From PC0:

ping 10.0.0.3

👉 Should work (same LAN)

🔹 Cross Network Test (Important)

From PC0:

ping 192.168.1.1

👉 If configured correctly:

✔ Request will go → Switch → Router → Switch → PC3

🎬 Step 5: Use Simulation Mode

• Switch to Simulation Mode
• Enable all filters
• Run ping again
• Click Auto Capture / Play

🔍 What Happens Internally?

1️⃣ PC Sends Packet to Gateway

PC0 sees destination is different network

Sends packet to default gateway (router)

2️⃣ Router Processes Packet

Checks routing table

Forwards packet to correct interface

3️⃣ Packet Reaches Destination Network

Router → Switch → Target PC

⚠️ Common Mistakes

• ❌ Forgetting default gateway
• ❌ Not using no shutdown on router interfaces
• ❌ Wrong subnet mask
• ❌ Incorrect IP addressing

🔄 Real-World Use Case

This setup is used in:

• Office networks (different departments)
• Campus networks
• Enterprise environments

👉 Router connects multiple networks, switches connect devices within a network.

🧠 Key Concepts You Learned

• Routing between different networks
• Role of default gateway
• Router interface configuration
• Packet flow across networks

💡 Conclusion

This practical shows how a router enables communication between multiple LANs. While switches handle local traffic efficiently, routers make inter-network communication possible, forming the backbone of real-world networking.