Add a Third Department without Breaking Existing VLANs

Open the lab

1. Save the .swlab file without renaming its extension.
2. Open SwitchLab. Import and export controls currently require a desktop-width window. On a smaller screen, Tools → Fit brings the topology into view.
3. Select Import Sandbox (folder icon), choose the downloaded file, and confirm the device and cable counts below.
4. Select a device, then choose Open device on desktop or its name in the bottom bar on smaller screens. Select CLI for switches/routers or Desktop → Terminal for PCs. Enter enable only when the prompt ends in >.
5. Follow this page beside the simulator. Use a free account to export your work. Reimport the original download to restart; export any work you want to keep first.

Prerequisites

• Complete VLAN Guided Lab and distinguish VLAN membership from IP addressing.

Follow the CCNA study path · Browse all SwitchLab labs

Topology

8 devices · 7 links

Scenario

Operations has two new hosts, one in each closet. Their ports were patched into unrelated VLANs and the existing trunk carries only Students and Staff. Complete the expansion while retaining both working departments.

Objectives

• Translate the approved VLAN plan into switch configuration.
• Verify port membership and every trunk in the path.
• Preserve working traffic while proving the new department or uplink.

CCNA blueprint

200-301 v1.1 objectives — this lab covers the following specific skills, not every subtopic in the domain.

• 2.1.a — Configure data access VLANs.
• 2.2.a — Configure trunk ports and restricted VLAN carriage.
• 2.2.b — Use 802.1Q VLAN separation across switches.

Starting information

• PC5 and PC6 are Operations hosts on g0/3 of SW1 and SW2. They require VLAN 30 named OPERATIONS.
• Keep STUDENTS VLAN 10 and STAFF VLAN 20 and all their addresses and port memberships.
• Both g0/8 trunk endpoints must carry exactly VLANs 10,20,30. No inter-VLAN routing is requested.

Tasks

1. Establish a working-traffic baseline for Students and Staff and a failed baseline for Operations.
2. Audit every switch setting required to carry Operations across the closets; write a change plan before entering commands.
3. Implement VLAN 30 on both switches, the approved host memberships and the expanded trunk policy.
4. Test all three departments in both directions and inspect each changed port. Explain why fixing only the host ports or only the trunk would be insufficient.

Useful commands

show vlan brief
show interfaces trunk
show running-config interface g0/3
show running-config interface g0/8
copy running-config startup-config

Progressive hints

Verification

• PC5 and PC6 are Operations hosts on g0/3 of SW1 and SW2. They require VLAN 30 named OPERATIONS.
• Keep STUDENTS VLAN 10 and STAFF VLAN 20 and all their addresses and port memberships.
• Both g0/8 trunk endpoints must carry exactly VLANs 10,20,30. No inter-VLAN routing is requested.
• Student and Staff paths succeed in both directions; configuration output matches the required membership and trunk policy.
• Operations PC5 and PC6 also ping each other in both directions.

Solution / walkthrough

enable
configure terminal
vlan 30
name OPERATIONS
exit
interface g0/3
switchport mode access
switchport access vlan 30
exit
interface g0/8
switchport trunk allowed vlan 10,20,30
end
copy running-config startup-config

enable
configure terminal
vlan 30
name OPERATIONS
exit
interface g0/3
switchport mode access
switchport access vlan 30
exit
interface g0/8
switchport trunk allowed vlan 10,20,30
end
copy running-config startup-config

Previous lab

Provision Departmental Access Ports

Related labs

• VLAN Guided Lab
• Repair a Workstation in the Wrong VLAN

Related articles and tools

• Packet Tracer Lab - Legacy
• Concept reference
• Cisco CLI cheat sheet

Next recommended lab

Build and Inspect an 802.1Q Trunk