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How to Configure VLAN on Two Cisco Switches with Four PCs

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Absolutely. Here is a WordPress-ready blog post for a beginner-friendly Cisco VLAN lab using 2 switches and 4 PCs.

How to Configure VLAN on Two Cisco Switches with Four PCs

Introduction

VLAN (Virtual Local Area Network) is used to logically divide a physical network into multiple separate networks. VLANs help improve network security, management, and traffic control.

In this tutorial, we will configure VLANs using:

  • 2 Cisco switches
  • 4 PCs
  • VLAN 10 – SALES
  • VLAN 20 – IT
  • A trunk link between the two switches

The lab can be created easily in Cisco Packet Tracer.

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1. Network Topology

We will create the following topology:

             Trunk Link
        Fa0/24 -------- Fa0/24
       +--------+      +--------+
       | Switch1|------| Switch2|
       +--------+      +--------+
        |      |        |      |
       PC1    PC2      PC3    PC4

VLAN Design

DevicePortVLANIP Address
PC1SW1 Fa0/1VLAN 10192.168.10.2
PC2SW1 Fa0/2VLAN 20192.168.20.2
PC3SW2 Fa0/1VLAN 10192.168.10.3
PC4SW2 Fa0/2VLAN 20192.168.20.3

We will use:

  • VLAN 10 = SALES
  • VLAN 20 = IT
  • Switch-to-switch connection = Trunk

2. Connect the Devices

In Cisco Packet Tracer, add:

  • 2 × Cisco 2960 switches
  • 4 × PCs

Connect:

PC1 → Switch1 Fa0/1
PC2 → Switch1 Fa0/2

PC3 → Switch2 Fa0/1
PC4 → Switch2 Fa0/2

Switch1 Fa0/24 → Switch2 Fa0/24

For the connections, you can use Copper Straight-Through cables.

3. Configure Switch 1

Open Switch1 → CLI.

Enter:

enable
configure terminal

hostname SW1

Create VLAN 10

vlan 10
name SALES
exit

Create VLAN 20

vlan 20
name IT
exit

Now configure the PC ports.

PC1 – VLAN 10

interface fastethernet 0/1
switchport mode access
switchport access vlan 10
exit

PC2 – VLAN 20

interface fastethernet 0/2
switchport mode access
switchport access vlan 20
exit

4. Configure Trunk Port on Switch 1

The connection between the two switches must carry traffic from both VLAN 10 and VLAN 20.

Configure Fa0/24 as a trunk:

interface fastethernet 0/24
switchport mode trunk
exit

Save the configuration:

end
write memory

5. Configure Switch 2

Open Switch2 → CLI.

enable
configure terminal

hostname SW2

Create VLAN 10:

vlan 10
name SALES
exit

Create VLAN 20:

vlan 20
name IT
exit

Configure PC3 – VLAN 10

interface fastethernet 0/1
switchport mode access
switchport access vlan 10
exit

Configure PC4 – VLAN 20

interface fastethernet 0/2
switchport mode access
switchport access vlan 20
exit

6. Configure Trunk on Switch 2

Configure Fa0/24:

interface fastethernet 0/24
switchport mode trunk
exit

Save:

end
write memory

7. Configure IP Addresses on PCs

Now configure the IP addresses.

PC1

Go to:

PC1 → Desktop → IP Configuration

Enter:

IP Address:      192.168.10.2
Subnet Mask:     255.255.255.0

PC2

IP Address:      192.168.20.2
Subnet Mask:     255.255.255.0

PC3

IP Address:      192.168.10.3
Subnet Mask:     255.255.255.0

PC4

IP Address:      192.168.20.3
Subnet Mask:     255.255.255.0

A default gateway is not required for this basic Layer-2 VLAN lab because we are not configuring routing between VLANs.

8. Understanding How This Works

The important concept is that the same VLAN exists on both switches.

VLAN 10 – SALES

PC1
192.168.10.2
     |
     | VLAN 10
     |
   SW1
     |
     | TRUNK
     |
   SW2
     |
     | VLAN 10
     |
PC3
192.168.10.3

Therefore:

PC1 can communicate with PC3.

Similarly:

VLAN 20 – IT

PC2
192.168.20.2
     |
   SW1
     |
     | TRUNK
     |
   SW2
     |
PC4
192.168.20.3

Therefore:

PC2 can communicate with PC4.

9. Test the VLAN Configuration

Open PC1 → Desktop → Command Prompt.

Run:

ping 192.168.10.3

You should receive replies:

Reply from 192.168.10.3
Reply from 192.168.10.3
Reply from 192.168.10.3

This confirms that PC1 and PC3 are communicating through VLAN 10 across the trunk.

Now test PC2:

ping 192.168.20.3

PC2 should successfully communicate with PC4 through VLAN 20.

10. Test VLAN Isolation

Now try:

From PC1

ping 192.168.20.2

This should fail.

Why?

PC1 is in:

VLAN 10

while PC2 is in:

VLAN 20

A normal Layer-2 switch does not route traffic between different VLANs.

11. Verify VLANs on the Switch

On SW1 and SW2, run:

show vlan brief

You should see something similar to:

VLAN Name                             Status    Ports
---- -------------------------------- --------- ----------------
1    default                          active    ...
10   SALES                            active    Fa0/1
20   IT                               active    Fa0/2

12. Verify the Trunk

Run:

show interfaces trunk

You should see Fa0/24 operating as a trunk.

For example:

Port        Mode         Encapsulation  Status
Fa0/24      on           802.1q         trunking

The trunk allows multiple VLANs to travel between the switches.

13. Complete Configuration

Switch 1

enable
configure terminal

hostname SW1

vlan 10
name SALES
exit

vlan 20
name IT
exit

interface fastethernet 0/1
switchport mode access
switchport access vlan 10
exit

interface fastethernet 0/2
switchport mode access
switchport access vlan 20
exit

interface fastethernet 0/24
switchport mode trunk
exit

end
write memory

Switch 2

enable
configure terminal

hostname SW2

vlan 10
name SALES
exit

vlan 20
name IT
exit

interface fastethernet 0/1
switchport mode access
switchport access vlan 10
exit

interface fastethernet 0/2
switchport mode access
switchport access vlan 20
exit

interface fastethernet 0/24
switchport mode trunk
exit

end
write memory

14. Final Network Diagram

                    TRUNK
              Fa0/24 ↔ Fa0/24
             +----------------+
             |                |
        +---------+      +---------+
        |   SW1   |      |   SW2   |
        +---------+      +---------+
          |      |         |      |
        Fa0/1  Fa0/2     Fa0/1  Fa0/2
          |      |         |      |
         PC1    PC2       PC3    PC4
          |      |         |      |
       VLAN 10 VLAN 20  VLAN 10 VLAN 20

Expected Results

TestResult
PC1 → PC3✅ Works
PC2 → PC4✅ Works
PC1 → PC2❌ Does not work
PC1 → PC4❌ Does not work
PC3 → PC4❌ Does not work

Conclusion

In this lab, we configured VLAN 10 and VLAN 20 on two Cisco switches and connected the switches using a trunk link.

The important commands to remember are:

vlan 10
switchport mode access
switchport access vlan 10

and for the connection between switches:

switchport mode trunk

This is a basic but important Cisco networking lab for understanding VLANs, access ports, trunk ports, and VLAN isolation.

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