6.3.2.4 Lab – Configuring Per-Interface Inter-VLAN Routing - Answers

Certification Answers

6.3.2.4 Lab – Configuring Per-Interface Inter-VLAN Routing (Instructor Version)

Instructor Note: Red font color or Gray highlights indicate text that appears in the instructor copy only.

Topology

Addressing Table

Device Interface IP Address Subnet Mask Default Gateway
R1 G0/0 192.168.20.1 255.255.255.0 N/A
G0/1 192.168.10.1 255.255.255.0 N/A
S1 VLAN 10 192.168.10.11 255.255.255.0 192.168.10.1
S2 VLAN 10 192.168.10.12 255.255.255.0 192.168.10.1
PC-A NIC 192.168.10.3 255.255.255.0 192.168.10.1
PC-B NIC 192.168.20.3 255.255.255.0 192.168.20.1

Objectives

  • Part 1: Build the Network and Configure Basic Device Settings
  • Part 2: Configure Switches with VLANs and Trunking
  • Part 3: Verify Trunking, VLANs, Routing, and Connectivity

Background / Scenario

Legacy inter-VLAN routing is seldom used in today’s networks; however, it is helpful to configure and understand this type of routing before moving on to router-on-a-stick (trunk-based) inter-VLAN routing or configuring Layer-3 switching. Also, you may encounter per-interface inter-VLAN routing in organizations with very small networks. One of the benefits of legacy inter-VLAN routing is ease of configuration.

In this lab, you will set up one router with two switches attached via the router Gigabit Ethernet interfaces. Two separate VLANs will be configured on the switches, and you will set up routing between the VLANs.

Note: This lab provides minimal assistance with the actual commands necessary to configure the router and switches. The required switch VLAN configuration commands are provided in Appendix A of this lab. Test your knowledge by trying to configure the devices without referring to the appendix.

Note: The routers used with CCNA hands-on labs are Cisco 1941 Integrated Services Routers (ISRs) with Cisco IOS, Release 15.2(4)M3 (universalk9 image). The switches used are Cisco Catalyst 2960s with Cisco IOS, Release 15.0(2) (lanbasek9 image). Other routers, switches and Cisco IOS versions can be used. Depending on the model and Cisco IOS version, the commands available and output produced might vary from what is shown in the labs. Refer to the Router Interface Summary Table at the end of this lab for the correct interface identifiers.

Note: Make sure that the routers and switches have been erased and have no startup configurations. If you are unsure, contact your instructor.

Instructor Note: Refer to the Instructor Lab Manual for the procedures to initialize and reload devices.

Required Resources

  • 1 Router (Cisco 1941 with Cisco IOS Release 15.2(4)M3 universal image or comparable)
  • 2 Switches (Cisco 2960 with Cisco IOS Release 15.0(2) lanbasek9 image or comparable)
  • 2 PCs (Windows 7, Vista, or XP with 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

Part 1: Build the Network and Configure Basic Device Settings

In Part 1, you will set up the network topology and clear any configurations, if necessary.

Step 1: Cable the network as shown in the topology.
Step 2: Initialize and reload the router and switches.
Step 3: Configure basic settings for R1.

a. Console into R1 and enter global configuration mode.

b. Copy the following basic configuration and paste it to the running-configuration on R1.

no ip domain-lookup
hostname R1
service password-encryption
enable secret class
banner motd #
Unauthorized access is strictly prohibited. #
line con 0
password cisco
login
logging synchronous
line vty 0 4
password cisco
login

c. Configure addressing on G0/0 and G0/1 and enable both interfaces.

d. Copy the running configuration to the startup configuration.

Step 4: Configure basic settings on both switches.

a. Console into the switch and enter global configuration mode.

b. Copy the following basic configuration and paste it to running-configuration on the switch.

no ip domain-lookup
service password-encryption
enable secret class
banner motd #
Unauthorized access is strictly prohibited. #
Line con 0
password cisco
login
logging synchronous
line vty 0 15
password cisco
login
exit

c. Configure the host name as shown in the topology.

d. Copy the running configuration to the startup configuration.

Step 5: Configure basic settings on PC-A and PC-B.

Configure PC-A and PC-B with IP addresses and a default gateway address according to the Addressing Table.

Part 2: Configure Switches with VLANs and Trunking

In Part 2, you will configure the switches with VLANs and trunking.

Step 1: Configure VLANs on S1.

a. On S1, create VLAN 10. Assign Student as the VLAN name.

b. Create VLAN 20. Assign Faculty-Admin as the VLAN name.

c. Configure F0/1 as a trunk port.

d. Assign ports F0/5 and F0/6 to VLAN 10 and configure both F0/5 and F0/6 as access ports.

e. Assign an IP address to VLAN 10 and enable it. Refer to the Addressing Table.

f. Configure the default gateway according to the Addressing Table.

Step 2: Configure VLANs on S2.

a. On S2, create VLAN 10. Assign Student as the VLAN name.

b. Create VLAN 20. Assign Faculty-Admin as the VLAN name.

c. Configure F0/1 as a trunk port.

d. Assign ports F0/11 and F0/18 to VLAN 20 and configure both F0/11 and F0/18 as access ports.

e. Assign an IP address to VLAN 10 and enable it. Refer to the Addressing Table.

f. Configure the default gateway according to the Addressing Table.

Part 3: Verify Trunking, VLANs, Routing, and Connectivity

Step 1: Verify the R1 routing table.

a. On R1, issue the show ip route command. What routes are listed on R1? ___________________
The 192.168.10.0/24 and 192.168.20.0/24 networks are listed on R1.

R1# show ip route
*Mar 25 15:05:00.003: %SYS-5-CONFIG_I: Configured from console by console
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       + - replicated route, % - next hop override
Gateway of last resort is not set
      192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.10.0/24 is directly connected, GigabitEthernet0/1
L        192.168.10.1/32 is directly connected, GigabitEthernet0/1
      192.168.20.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.20.0/24 is directly connected, GigabitEthernet0/0
L        192.168.20.1/32 is directly connected, GigabitEthernet0/0

b. On both S1 and S2, issue the show interface trunk command. Is the F0/1 port on both switches set to trunk? ______
Yes

S1# show interface trunk

Port       Mode            Encapsulation  Status       Native vlan
Fa0/1      on              802.1q         trunking     1

Port       Vlans allowed on trunk
Fa0/1      1-4094

Port       Vlans allowed and active in management domain
Fa0/1      1,10,20

Port       Vlans in spanning tree forwarding state and not pruned
Fa0/1      1,10,20

c. Issue a show vlan brief command on both S1 and S2. Verify that VLANs 10 and 20 are active and that the proper ports on the switches are in the correct VLANs. Why is F0/1 not listed in any of the active VLANs? ___________________
It is a trunk port and is not assigned to a VLAN.

S1# show vlan brief
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/2, Fa0/3, Fa0/4, 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
10   Student                          active    Fa0/5, Fa0/6
20   Faculty-Admin                    active
1002 fddi-default                     act/unsup
1003 token-ring-default               act/unsup
1004 fddinet-default                  act/unsup
1005 trnet-default                    act/unsup

S2# show vlan brief

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/2, Fa0/3, Fa0/4, Fa0/5
                                                Fa0/6, Fa0/7, Fa0/8, Fa0/9
                                                Fa0/10, 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
10   Student                          active
20   Faculty-Admin                    active    Fa0/11, Fa0/18
1002 fddi-default                     act/unsup
1003 token-ring-default               act/unsup
1004 fddinet-default                  act/unsup
1005 trnet-default                    act/unsup

d. Ping from PC-A in VLAN 10 to PC-B in VLAN 20. If Inter-VLAN routing is functioning correctly, the pings between the 192.168.10.0 network and the 192.168.20.0 should be successful.

Note: It may be necessary to disable the PC firewall to ping between PCs.

e. Verify connectivity between devices. You should be able to ping between all devices. Troubleshoot if you are not successful.

Reflection

What is an advantage of using legacy inter-VLAN routing? ___________________
Answers may vary. Configuration of both the router and switches is relatively easy and straightforward. No subinterfaces are required on the router and trunking does NOT have to be configured between the router and switch.

Router Interface Summary Table

Router Interface Summary
Router Model Ethernet Interface #1 Ethernet Interface #2 Serial Interface #1 Serial Interface #2
1800 Fast Ethernet 0/0 (F0/0) Fast Ethernet 0/1 (F0/1) Serial 0/0/0 (S0/0/0) Serial 0/0/1 (S0/0/1)
1900 Gigabit Ethernet 0/0 (G0/0) Gigabit Ethernet 0/1 (G0/1) Serial 0/0/0 (S0/0/0) Serial 0/0/1 (S0/0/1)
2801 Fast Ethernet 0/0 (F0/0) Fast Ethernet 0/1 (F0/1) Serial 0/1/0 (S0/1/0) Serial 0/1/1 (S0/1/1)
2811 Fast Ethernet 0/0 (F0/0) Fast Ethernet 0/1 (F0/1) Serial 0/0/0 (S0/0/0) Serial 0/0/1 (S0/0/1)
2900 Gigabit Ethernet 0/0 (G0/0) Gigabit Ethernet 0/1 (G0/1) Serial 0/0/0 (S0/0/0) Serial 0/0/1 (S0/0/1)
Note: To find out how the router is configured, look at the interfaces to identify the type of router and how many interfaces the router has. There is no way to effectively list all the combinations of configurations for each router class. This table includes identifiers for the possible combinations of Ethernet and Serial interfaces in the device. The table does not include any other type of interface, even though a specific router may contain one. An example of this might be an ISDN BRI interface. The string in parenthesis is the legal abbreviation that can be used in Cisco IOS commands to represent the interface.

Appendix A: Configuration Commands

S1(config)# vlan 10
S1(config-vlan)# name Student
S1(config-vlan)# exit
S1(config)# vlan 20
S1(config-vlan)# name Faculty-Admin
S1(config-vlan)# exit
S1(config)# interface f0/1
S1(config-if)# switchport mode trunk
S1(config-if)# interface range f0/5 – 6
S1(config-if-range)# switchport mode access
S1(config-if-range)# switchport access vlan 10
S1(config-if-range)# interface vlan 10
S1(config-if)# ip address 192.168.10.11 255.255.255.0
S1(config-if)# no shut
S1(config-if)# exit
S1(config)# ip default-gateway 192.168.10.1
S2(config)# vlan 10
S2(config-vlan)# name Student
S2(config-vlan)# exit
S2(config)# vlan 20
S2(config-vlan)# name Faculty-Admin
S2(config-vlan)# exit
S2(config)# interface f0/1
S2(config-if)# switchport mode trunk
S2(config-if)# interface f0/11
S2(config-if)# switchport mode access
S2(config-if)# switchport access vlan 20
S2(config-if)# interface f0/18
S2(config-if)# switchport mode access
S2(config-if)# switchport access vlan 20
S2(config-if-range)# interface vlan 10
S2(config-if)#ip address 192.168.10.12 255.255.255.0
S2(config-if)# no shut
S2(config-if)# exit
S2(config)# ip default-gateway 192.168.10.1

Device Configs

Instructor Note: The VLANs configured do not display in the switch running configuration but are stored in the vlan.dat file.
R1#show run
Building configuration...
Current configuration : 1640 bytes
!
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!
!
enable secret 4 06YFDUHH61wAE/kLkDq9BGho1QM5EnRtoyr8cHAUg.2
!
no aaa new-model
!
!
!
!
no ip domain lookup
ip cef
no ipv6 cef
!
multilink bundle-name authenticated
!
!
!
!
redundancy
!
!
!
!
!
!
!
interface Embedded-Service-Engine0/0
no ip address
shutdown
!
interface GigabitEthernet0/0
ip address 192.168.20.1 255.255.255.0
duplex auto
speed auto
!
interface GigabitEthernet0/1
ip address 192.168.10.1 255.255.255.0
duplex auto
speed auto
!
interface Serial0/0/0
no ip address
shutdown
clock rate 2000000
!
interface Serial0/0/1
no ip address
shutdown
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
!
!
!
control-plane
!
!
!
line con 0
password cisco
login
line aux 0
line 2
no activation-character
no exec
transport preferred none
transport input all
transport output pad telnet rlogin lapb-ta mop udptn v120 ssh
stopbits 1
line vty 0 4
password cisco
login
transport input all
!
scheduler allocate 20000 1000
!
end
S1# show vlan brief
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/2, Fa0/3, Fa0/4, 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
10   Student                          active    Fa0/5, Fa0/6
20   Faculty-Admin                    active
1002 fddi-default                     act/unsup
1003 token-ring-default               act/unsup
1004 fddinet-default                  act/unsup
1005 trnet-default                    act/unsup

S1#show run
Building configuration...
Current configuration : 1644 bytes
!
version 15.0
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname S1
!
!
enable secret 4 06YFDUHH61wAE/kLkDq9BGho1QM5EnRtoyr8cHAUg.2
!
no aaa new-model
system mtu routing 1500
!
!
no ip domain-lookup
!
interface FastEthernet0/1
switchport mode trunk
!
interface FastEthernet0/2
!
interface FastEthernet0/3
!
interface FastEthernet0/4
!
interface FastEthernet0/5
switchport access vlan 10
switchport mode access
!
interface FastEthernet0/6
switchport access vlan 10
switchport mode access
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface FastEthernet0/9
!
interface FastEthernet0/10
!
interface FastEthernet0/11
!
interface FastEthernet0/12
!
interface FastEthernet0/13
!
interface FastEthernet0/14
!
interface FastEthernet0/15
!
interface FastEthernet0/16
!
interface FastEthernet0/17
!
interface FastEthernet0/18
!
interface FastEthernet0/19
!
interface FastEthernet0/20
!
interface FastEthernet0/21
!
interface FastEthernet0/22
!
interface FastEthernet0/23
!
interface FastEthernet0/24
!
interface GigabitEthernet0/1
!
interface GigabitEthernet0/2
!
interface Vlan1
no ip address
shutdown
!
interface Vlan10
ip address 192.168.10.11 255.255.255.0
!
ip default-gateway 192.168.10.1
ip http server
ip http secure-server
!
!
line con 0
password cisco
login
line vty 0 4
password cisco
login
line vty 5 15
password cisco
login
!
end
S2# show vlan brief
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa0/2, Fa0/3, Fa0/4, Fa0/5
                                                Fa0/6, Fa0/7, Fa0/8, Fa0/9
                                                Fa0/10, 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
10   Student                          active
20   Faculty-Admin                    active    Fa0/11, Fa0/18
1002 fddi-default                     act/unsup
1003 token-ring-default               act/unsup
1004 fddinet-default                  act/unsup
1005 trnet-default                    act/unsup

S2#sh run
Building configuration...
Current configuration : 1644 bytes
!
version 15.0
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname S2
!
enable secret 4 06YFDUHH61wAE/kLkDq9BGho1QM5EnRtoyr8cHAUg.2
!
no aaa new-model
system mtu routing 1500
!
!
no ip domain-lookup
!
interface FastEthernet0/1
switchport mode trunk
!

interface FastEthernet0/10
!
interface FastEthernet0/11
switchport access vlan 20
switchport mode access
!
interface FastEthernet0/12
!
interface FastEthernet0/13
!
interface FastEthernet0/14
!
interface FastEthernet0/15
!
interface FastEthernet0/16
!
interface FastEthernet0/17
!
interface FastEthernet0/18
switchport access vlan 20
switchport mode access
!
!interface FastEthernet0/19
!
interface FastEthernet0/20
!
interface FastEthernet0/21
!
interface FastEthernet0/22
!
interface FastEthernet0/23
!
interface FastEthernet0/24
!
interface GigabitEthernet0/1
!
interface GigabitEthernet0/2
!
interface Vlan1
no ip address
shutdown
!
interface Vlan10
ip address 192.168.10.12 255.255.255.0
!
ip default-gateway 192.168.10.1
ip http server
ip http secure-server
!
line con 0
line vty 0 4
password cisco
login
line vty 5 15
password cisco
login
end