Lab - Implement VLANs and Trunking (Instructor Version)
Topology
Addressing Table
| Device | Interface | IP Address | Subnet Mask |
|---|---|---|---|
| S1 | VLAN 10 | 192.168.10.11 | 255.255.255.0 |
| VLAN 20 | 192.168.20.11 | 255.255.255.0 | |
| VLAN 30 | 192.168.30.11 | 255.255.255.0 | |
| S2 | VLAN 10 | 192.168.10.12 | 255.255.255.0 |
| PC-A | NIC | 192.168.20.13 | 255.255.255.0 |
| PC-B | NIC | 192.168.30.13 | 255.255.255.0 |
VLAN Table
| VLAN | Name | Interface Assigned |
|---|---|---|
| 10 | Management | S1: VLAN 10 S2: VLAN 10 |
| 20 | Sales | S1: VLAN 20 and F0/6 |
| 30 | Operations | S1: VLAN 30 S2: F0/18 |
| 999 | ParkingLot | S1: F0/2-5, F0/7-24, G0/1-2 S2: F0/2-17, F0/19-24, G0/1-2 |
| 1000 | Native | N/A |
Objectives
- Part 1: Build the Network and Configure Basic Device Settings
- Part 2: Create VLANs and Assign Switch Ports
- Part 3: Configure an 802.1Q Trunk between the Switches
Background / Scenario
Modern switches use virtual local-area networks (VLANs) to improve network performance by separating large Layer 2 broadcast domains into smaller ones. VLANs address scalability, security, and network management. In general, VLANs make it easier to design a network to support the goals of an organization. Communication between VLANs requires a device operating at Layer 3 of the OSI model.
VLAN trunks are used to span VLANs across multiple devices. Trunks allow the traffic from multiple VLANs to travel over a single link, while keeping the VLAN identification and segmentation intact.
In this lab, you will create VLANs on both switches in the topology, assign VLANs to switch access ports, verify that VLANs are working as expected and create VLAN trunks between the two switches.
Note: The switches used with CCNA hands-on labs are Cisco Catalyst 2960s with Cisco IOS Release 15.2(2) (lanbasek9 image). Other switches and Cisco IOS versions can be used. Depending on the model and Cisco IOS version, the commands available and the output produced might vary from what is shown in the labs. Refer to the Router Interface Summary Table at the end of the lab for the correct interface identifiers.
Note: Ensure that the switches have been erased and have no startup configurations. If you are unsure contact your instructor.
Required Resources
- 2 Switches (Cisco 2960 with Cisco IOS Release 15.2(2) lanbasek9 image or comparable)
- 2 PCs (Windows with a terminal emulation program, such as Tera Term)
- Console cables to configure the Cisco IOS devices via the console ports
- Ethernet cables as shown in the topology
Instructions
Part 1: Build the Network and Configure Basic Device Settings
In Part 1, you will set up the network topology and configure basic settings on the PC hosts and switches.
Step 1: Cable the network as shown in the topology.
Attach the devices as shown in the topology diagram, and cable as necessary.
Step 2: Configure basic settings for each switch.
a. Console into the switch and enable privileged EXEC mode.
b. Assign a device name to the switch.
switch(config)# hostname S1 switch(config)# hostname S2
c. Disable DNS lookup.
S1(config)# no ip domain-lookup S2(config)# no ip domain-lookup
d. Assign class as the privileged EXEC encrypted password.
S1(config)# enable secret class S2(config)# enable secret class
e. Assign cisco as the console password and enable login.
S1(config)# line console 0 S1(config-line)# password cisco S1(config-line)# login S2(config)# line console 0 S2(config-line)# password cisco S2(config-line)# login
f. Assign cisco as the VTY password and enable login.
S1(config)# line vty 0 15 S1(config-line)# password cisco S1(config-line)# login S2(config)# line vty 0 15 S2(config-line)# password cisco S2(config-line)# login
g. Encrypt the plaintext passwords.
S1(config)# service password-encryption S2(config)# service password-encryption
h. Create a banner that warns anyone accessing the device that unauthorized access is prohibited.
S1(config)# banner motd $ Authorized Users Only! $ S2(config)# banner motd $ Authorized Users Only! $
i. Copy the running configuration to the startup configuration.
S1# copy running-config startup-config S2# copy running-config startup-config
Step 3: Configure PC hosts.
Refer to the Addressing Table for PC host address information.
Part 2: Create VLANs and Assign Switch Ports
In Part 2, you will create VLANs as specified in the table above on both switches. You will then assign the VLANs to the appropriate interface. The show vlan brief command is used to verify your configuration settings. Complete the following tasks on each switch.
Step 1: Create VLANs on both switches.
a. Create and name the required VLANs on each switch from the table above.
S1(config)# vlan 10 S1(config-vlan)# name Management S1(config-vlan)# vlan 20 S1(config-vlan)# name Sales S1(config-vlan)# vlan 30 S1(config-vlan)# name Operations S1(config-vlan)# vlan 999 S1(config-vlan)# name ParkingLot S1(config-vlan)# vlan 1000 S1(config-vlan)# name Native S2(config)# vlan 10 S2(config-vlan)# name Management S2(config-vlan)# vlan 20 S2(config-vlan)# name Sales S2(config-vlan)# vlan 30 S2(config-vlan)# name Operations S2(config-vlan)# vlan 999 S2(config-vlan)# name ParkingLot S2(config-vlan)# vlan 1000 S2(config-vlan)# name Native
b. Configure the management interface on each switch using the IP address information in the Addressing Table.
S1(config)# interface vlan 10 S1(config-if)# ip address 192.168.10.11 255.255.255.0 S1(config-if)# interface vlan 20 S1(config-if)# ip address 192.168.20.11 255.255.255.0 S1(config-if)# interface vlan 30 S1(config-if)# ip address 192.168.30.11 255.255.255.0 S2(config)# interface vlan 10 S2(config-if)# ip address 192.168.10.12 255.255.255.0
c. Assign all unused ports on the switch to the ParkingLot VLAN, configure them for static access mode, and administratively deactivate them.
S1(config)# interface range f0/2 - 5, f0/7 - 24, g0/1 - 2 S1(config-if-range)# switchport mode access S1(config-if-range)# switchport access vlan 999 S1(config-if-range)# shutdown S2(config)# interface range f0/2 - 17, f0/19 - 24, g0/1 - 2 S2(config-if-range)# switchport mode access S2(config-if-range)# switchport access vlan 999 S2(config-if-range)# shutdown
Step 2: Assign VLANs to the correct switch interfaces.
a. Assign used ports to the appropriate VLAN (specified in the VLAN table above) and configure them for static access mode.
S1(config)# interface f0/6 S1(config-if)# switchport mode access S1(config-if)# switchport access vlan 20 S2(config)# interface f0/18 S2(config-if)# switchport mode access S2(config-if)# switchport access vlan 30
b. Verify that the VLANs are assigned to the correct interfaces.
S1# show vlan brief
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa0/1
10 Management active
20 Sales active Fa0/6
30 Operations active
999 ParkingLot active Fa0/2, Fa0/3, Fa0/4, Fa0/5
Fa0/7, Fa0/8, Fa0/9, Fa0/10
Fa0/11, Fa0/12, Fa0/13, Fa0/14
Fa0/15, Fa0/16, Fa0/17, Fa0/18
Fa0/19, Fa0/20, Fa0/21, Fa0/22
Fa0/23, Fa0/24, Gi0/1, Gi0/2
1000 Native active
<output omitted>
S2# show vlan brief
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa0/1
10 Management active
20 Sales active
30 Operations active Fa0/18
999 ParkingLot active Fa0/2, Fa0/3, Fa0/4, Fa0/5
Fa0/6, Fa0/7, Fa0/8, Fa0/9
Fa0/10, Fa0/11, Fa0/12, Fa0/13
Fa0/14, Fa0/15, Fa0/16, Fa0/17
Fa0/19, Fa0/20, Fa0/21, Fa0/22
Fa0/23, Fa0/24, Gi0/1, Gi0/2
<output omitted>
Part 3: Configure an 802.1Q Trunk Between the Switches
In Part 3, you will manually configure interface F0/1 as a trunk.
Step 1: Manually configure trunk interface F0/1.
a. Change the switchport mode on interface F0/1 to force trunking. Make sure to do this on both switches.
S1(config)# interface f0/1 S1(config-if)# switchport mode trunk S2(config)# interface f0/1 S2(config-if)# switchport mode trunk
b. Set the native VLAN to 1000 on both switches.
S1(config-if)# switchport trunk native vlan 1000 S2(config-if)# switchport trunk native vlan 1000
c. As another part of trunk configuration, specify that only VLANs 10, 20, 30, and 1000 are allowed to cross the trunk.
S1(config-if)# switchport trunk allowed vlan 10,20,30,1000 S2(config-if)# switchport trunk allowed vlan 10,20,30,1000
d. Issue the show interfaces trunk command to verify trunking ports, the native VLAN and allowed VLANs across the trunk.
S1# show interfaces trunk Port Mode Encapsulation Status Native vlan Fa0/1 on 802.1q trunking 1000 Port Vlans allowed on trunk Fa0/1 10,20,30,1000 Port Vlans allowed and active in management domain Fa0/1 10,20,30,1000 Port Vlans in spanning tree forwarding state and not pruned Fa0/1 10,20,30,1000
Step 2: Verify connectivity.
Verify connectivity within a VLAN. For example, PC-A should be able to ping S1 VLAN 20 successfully.
Were the pings from PC-B to S2 successful? Explain.
The pings were not successful because they are not in the same VLAN. A router is needed to communicate between VLANs.
Device Configs - Final
Switch S1
! ============================================================== !--- Lab - Implement VLANs and Trunking !--- ANSWER SCRIPT FOR SWITCH S1 !--- Usage: this switch starts fresh (no startup-config) - console in, "enable" into privileged EXEC mode, then paste this whole file. Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless. !--- Verified against this lab's own "Device Configs - Final" section - everything below matches it exactly. No functional errors found (this lab's port ranges are correct throughout, unlike a similar earlier lab where S2's unused-port range accidentally included the PC's own port). ! ============================================================== enable configure terminal ! -------------------------------------------------------------- !--- Part 1: Basic switch settings ! -------------------------------------------------------------- hostname S1 no ip domain-lookup enable secret class service password-encryption banner motd $ Authorized Users Only! $ line console 0 password cisco login exit line vty 0 15 password cisco login exit end copy running-config startup-config configure terminal ! -------------------------------------------------------------- !--- Part 2, Step 1: Create and name all five VLANs ! -------------------------------------------------------------- vlan 10 name Management vlan 20 name Sales vlan 30 name Operations vlan 999 name ParkingLot vlan 1000 name Native ! -------------------------------------------------------------- !--- Part 2, Step 2: Configure the three management SVIs ! -------------------------------------------------------------- !--- S1 hosts all three of its own subnet gateways (VLAN 10 management, VLAN 20 Sales, VLAN 30 Operations) - S2 only needs VLAN 10 for its own management, since VLAN 30's actual host (PC-B) lives on S2 but VLAN 30's gateway lives here on S1. interface Vlan10 ip address 192.168.10.11 255.255.255.0 exit interface Vlan20 ip address 192.168.20.11 255.255.255.0 exit interface Vlan30 ip address 192.168.30.11 255.255.255.0 exit ! -------------------------------------------------------------- !--- Part 2, Step 3: Park every unused port in VLAN 999 and shut it down ! -------------------------------------------------------------- interface range FastEthernet0/2 - 5, FastEthernet0/7 - 24, GigabitEthernet0/1 - 2 switchport mode access switchport access vlan 999 shutdown exit ! -------------------------------------------------------------- !--- Part 2, Step 2.2.1: Assign PC-A's port to VLAN 20 (Sales) ! -------------------------------------------------------------- interface FastEthernet0/6 switchport mode access switchport access vlan 20 exit ! -------------------------------------------------------------- !--- Part 3: Configure the 802.1Q trunk to S2 ! -------------------------------------------------------------- !--- Native VLAN 1000 (not the default VLAN 1) keeps untagged control-plane traffic off the well-known default VLAN. Only VLANs 10, 20, 30, and 1000 are allowed to cross - VLAN 999 (ParkingLot) deliberately never leaves either switch. interface FastEthernet0/1 switchport mode trunk switchport trunk native vlan 1000 switchport trunk allowed vlan 10,20,30,1000 exit end ! -------------------------------------------------------------- !--- Operational habit: save again now that Parts 2-3 have changed the configuration. ! -------------------------------------------------------------- copy running-config startup-config ! ============================================================== !--- Verification: !--- S1# show vlan brief -> VLAN 20 shows Fa0/6; VLAN 999 shows all 26 parked ports; VLAN 10/30/1000 show none (SVI/trunk-only) !--- S1# show interfaces trunk -> Fa0/1 trunking, native VLAN 1000, allowed VLANs 10,20,30,1000 !--- From PC-A, ping S1's VLAN 20 address (192.168.20.11) -> success !--- From PC-B, ping S2 -> fails (different VLAN from S2's own management address) - matches the lab's own expected answer, since no Layer 3 device routes between VLANs here ! ==============================================================
Switch S2
! ============================================================== !--- Lab - Implement VLANs and Trunking !--- ANSWER SCRIPT FOR SWITCH S2 !--- Usage: this switch starts fresh (no startup-config) - console in, "enable" into privileged EXEC mode, then paste this whole file. Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless. !--- Verified against this lab's own "Device Configs - Final" section - everything below matches it exactly. No functional errors found. ! ============================================================== enable configure terminal ! -------------------------------------------------------------- !--- Part 1: Basic switch settings ! -------------------------------------------------------------- hostname S2 no ip domain-lookup enable secret class service password-encryption banner motd $ Authorized Users Only! $ line console 0 password cisco login exit line vty 0 15 password cisco login exit end copy running-config startup-config configure terminal ! -------------------------------------------------------------- !--- Part 2, Step 1: Create and name all five VLANs (identical set to S1) ! -------------------------------------------------------------- vlan 10 name Management vlan 20 name Sales vlan 30 name Operations vlan 999 name ParkingLot vlan 1000 name Native ! -------------------------------------------------------------- !--- Part 2, Step 2: Configure S2's own management SVI ! -------------------------------------------------------------- !--- S2 only needs VLAN 10 for its own management address - VLAN 30's gateway (which PC-B, on F0/18 below, actually needs) lives on S1, reached over the trunk. interface Vlan10 ip address 192.168.10.12 255.255.255.0 exit ! -------------------------------------------------------------- !--- Part 2, Step 3: Park every unused port in VLAN 999 and shut it down ! -------------------------------------------------------------- !--- Note the gap at F0/18 - that's PC-B's port, handled separately below. interface range FastEthernet0/2 - 17, FastEthernet0/19 - 24, GigabitEthernet0/1 - 2 switchport mode access switchport access vlan 999 shutdown exit ! -------------------------------------------------------------- !--- Part 2, Step 2.2.1: Assign PC-B's port to VLAN 30 (Operations) ! -------------------------------------------------------------- interface FastEthernet0/18 switchport mode access switchport access vlan 30 exit ! -------------------------------------------------------------- !--- Part 3: Configure the 802.1Q trunk to S1 ! -------------------------------------------------------------- !--- Must match S1's trunk settings exactly - same native VLAN, same allowed-VLAN list. interface FastEthernet0/1 switchport mode trunk switchport trunk native vlan 1000 switchport trunk allowed vlan 10,20,30,1000 exit end ! -------------------------------------------------------------- !--- Operational habit: save again now that Parts 2-3 have changed the configuration. ! -------------------------------------------------------------- copy running-config startup-config ! ============================================================== !--- Verification: !--- S2# show vlan brief -> VLAN 30 shows Fa0/18; VLAN 999 shows all 26 parked ports !--- S2# show interfaces trunk -> Fa0/1 trunking, native VLAN 1000, allowed VLANs 10,20,30,1000 !--- From PC-B, ping S1's VLAN 30 address (192.168.30.11) -> success (over the trunk) !--- From PC-B, ping S2 -> fails, per the lab's own expected answer (different VLAN, no inter-VLAN routing device present) ! ==============================================================
