I did this Practice Exercise for CCNA Course ( Neil Anderson )

Stage 1

Initial Setup:

• All switches and routers were in factory default state.
• Verified VLAN database using show vlan brief – only default VLANs existed.

🔧 Configuration Steps:

1. Checked default switchport settings using:

   show interfaces switchport

2. Configured trunk links between switches:

   interface Gi0/1
   switchport mode trunk
   switchport trunk native vlan 199
   

3. Configured VTP:

   • On SW1:

     vtp mode server
     vtp domain FLACKBOX
     

   • On SW2:

     vtp mode transparent
     vtp domain FLACKBOX
     

   • On SW3:

     vtp mode client
     vtp domain FLACKBOX
     

4. Created VLANs on SW1 (VTP Server):

   vlan 10
   name ENG
   vlan 20
   name SALES
   vlan 199
   name NATIVE
   

5. VLAN propagation:

   • Verified VLANs automatically synced to SW3 (Client).
   • SW2 remained unchanged (Transparent mode).

6. Set trunk native VLAN on all trunk ports for security:

   switchport trunk native vlan 199
   

7. Configured access ports for PCs:

   • Example on SW3:

     int range f0/1 - 2
     switchport mode access
     switchport access vlan 10
     int f0/3
     switchport mode access
     switchport access vlan 20
     

8. Resolved native VLAN mismatch errors:

   • Matched native VLAN (199) on both sides of trunk links.
   • STP blocking issues resolved.

✅ Verification:

• Verified VLANs using: show vlan brief
• Verified trunk status: show interfaces trunk
• Checked PC connectivity with ping commands (Eng1 ↔ Eng3, Sales1 ↔ Sales3)

✅ Stage 2: Inter-VLAN Routing - Option 1

Using Separate Physical Interfaces on Router (R1)

🔧 Router (R1) Configuration

1. Enable and assign IP addresses to interfaces:

   • FastEthernet0/0 (for ENG VLAN):

     interface FastEthernet0/0
     ip address 10.10.10.1 255.255.255.0
     no shutdown
     

   • FastEthernet0/1 (for Sales VLAN):

     interface FastEthernet0/1
     ip address 10.10.20.1 255.255.255.0
     no shutdown
     

✅ Both interfaces are UP and functioning

🔧 Switch (SW2) Configuration

1. VLAN Configuration:

   • VLAN 10 (ENG) and VLAN 20 (Sales) are already created:

     vlan 10
     name ENG
     
     vlan 20
     name Sales
     

2. Assign VLANs to Ports:

   • Fa0/1 → VLAN 10 (ENG):

     interface Fa0/1
     switchport mode access
     switchport access vlan 10
     

   • Fa0/2 → VLAN 20 (Sales):

     interface Fa0/2
     switchport mode access
     switchport access vlan 20
     

3. Trunk Port Configured:

   • Gig0/1 set as trunk with native VLAN 199:

     interface Gig0/1
     switchport trunk native vlan 199
     switchport mode trunk
     

✅ VLAN interfaces Vlan10 and Vlan20 are up

📡 Verification Steps

1. Connectivity from Eng1 (Fa0/1) to R1’s VLAN 20 (10.10.20.1)

   ⏳

2. Connectivity from Eng1 to Sales1 (across VLANs)

   

✅ Stage 3: Inter-VLAN Routing - Option 2

Router-on-a-Stick Configuration

🔧 Router (R1) Configuration

1. Clear Existing IPs on Physical Interface
   • Removed IPs from FastEthernet0/0 to prepare for subinterfaces.
2. Configure Sub-Interfaces on FastEthernet0/0:

   • For VLAN 10 (ENG):

     interface FastEthernet0/0.10
     encapsulation dot1Q 10
     ip address 10.10.10.1 255.255.255.0
     

   • For VLAN 20 (Sales):

     interface FastEthernet0/0.20
     encapsulation dot1Q 20
     ip address 10.10.20.1 255.255.255.0
     

✅ Both sub-interfaces are UP and functional

✅ *FastEthernet0/0 now acts as trunk carrying tagged VLAN traffic*

🔧 Switch (SW2) Configuration

1. VLAN Setup:

   • VLANs already exist:

     vlan 10
     name ENG
     vlan 20
     name Sales
     vlan 199
     name NATIVE
     

2. Assign Access Ports:

   • Fa0/1 to VLAN 10 (ENG)

     interface Fa0/1
     switchport mode access
     switchport access vlan 10
     

   • Fa0/2 to VLAN 20 (Sales)

     interface Fa0/2
     switchport mode access
     switchport access vlan 20
     

3. Configure Trunk to Router:

   • Fa0/1 (connected to R1’s Fa0/0) as trunk:

     interface Fa0/1
     switchport trunk encapsulation dot1q
     switchport mode trunk
     switchport trunk allowed vlan 10,20
     

✅ Trunk operational and forwarding VLAN 10 and 20 traffic

1. Set Default Gateway on SW2:

   ip default-gateway 10.10.10.1
   

📡 Verification Steps

1. PC Eng1 (VLAN 10) should be able to:

   • ✅ Ping 10.10.20.1 (R1’s subinterface for VLAN 20)
   • ✅ Ping Sales1 PC

   

   Pinging Sales 3 from Eng 1

   

Pinging Eng1 from Sales 1

🎯 Conclusion

This lab successfully demonstrated three critical aspects of VLAN implementation:

• Basic VLAN Configuration: Established proper VLAN segmentation with VTP configuration across multiple switches
• Traditional Inter-VLAN Routing: Implemented routing using separate physical interfaces, proving the basic concept of inter-VLAN communication
• Router-on-a-Stick: Successfully configured and tested a more scalable inter-VLAN routing solution using subinterfaces

Key Learning Outcomes:

• Understanding of different VTP modes and their impact on VLAN propagation
• Practical experience with both physical and logical inter-VLAN routing methods
• Troubleshooting skills for native VLAN mismatches and connectivity issues

All configurations were verified with successful ping tests between VLANs, demonstrating a fully functional network design.