El Switch

Lab 4-1 Inter-VLAN Routing with an External Router
Topology Diagram

Objective
This lab configures inter-VLAN routing using an external router, also known as
a router-on-a-stick.
Scenario
Inter-VLAN routing using an external router can be a cost-effective solution
when it is necessary to segment a network into multiple broadcast domains. In
this scenario, we are splitting an existingnetwork into two separate VLANs on
the access layer switches, and using an external router to route between the
VLANs. We are using a 802.1q trunk between the switch and the Fast Ethernet
interface of the router for routing and management. Static routes are used
between the gateway router and the ISP router.
Step 1
Power up the switches and use the standard process for establishing aHyperTerminal console connection from a workstation to each switch in your
pod.
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CCNP: Building Multilayer Switched Networks v5.0 - Lab 4-1

Copyright © 2006, Cisco Systems, Inc

Remove all VLAN information and configurations that were previously entered
into your switches. (Refer to Lab 2.0a or 2.0b if needed.)
Step 2
Configure the ISP router for communication with your Gateway router.The
static route used for the internal networks provides a path for the local network
from the ISP. In addition, configure a loopback interface on the ISP router to
simulate an external network.
Router(config)# hostname ISP
ISP(config)# interface Loopback0
ISP(config-if)# ip address 200.200.200.1 255.255.255.0
ISP(config-if)# interface Serial0/0
ISP(config-if)# ip address 192.168.1.1255.255.255.0
ISP(config-if)# clockrate 64000
ISP(config-if)# no shutdown
ISP(config-if)# exit
ISP(config)# ip route 172.16.0.0 255.255.0.0 192.168.1.2

Configure the Gateway router to communicate with the ISP router. Notice the
use of a default static route here. The default route tells the router to send any
unknown traffic within the network to the ISP router.
Router(config)# hostnameGateway
Gateway(config)# interface Serial0/0
Gateway(config-if)# ip address 192.168.1.2 255.255.255.0
Gateway(config-if)# no shutdown
Gateway(config-if)# exit
Gateway(config)# ip route 0.0.0.0 0.0.0.0 192.168.1.1

1. Verify connectivity from the Gateway router using the ping command. Was
this ping successful?

Step 3
To differentiate between the devices, name the two access layer switchesusing
the hostname command. Configure the IP addresses on the management
VLAN according to the diagram. By default, VLAN 1 is used as the
management VLAN. Create a default gateway on both access layer switches
using the ip default-gateway ip_address command. Set an enable secret
password and configure the VTY lines for Telnet access to the switch.
The following is a sample configuration forthe 2960 switch ALS1:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# hostname ALS1
ALS1(config)# interface vlan 1
ALS1(config-if)# ip address 172.16.1.101 255.255.255.0

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CCNP: Building Multilayer Switched Networks v5.0 - Lab 4-1

Copyright © 2006, Cisco Systems, Inc

ALS1(config-if)# no shutdown
ALS1(config-if)# exitALS1(config)# ip default-gateway 172.16.1.1
ALS1(config)# enable secret cisco
ALS1(config)# line vty 0 15
ALS1(config-line)# password cisco
ALS1(config-line)# login
ALS1(config-line)# end

The following is a sample configuration for the 2960 switch ALS2:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# hostname ALS2
ALS2(config)#interface vlan 1
ALS2(config-if)# ip address 172.16.1.102 255.255.255.0
ALS2(config-if)# no shutdown
ALS2(config-if)# exit
ALS2(config)# ip default-gateway 172.16.1.1
ALS2(config)# enable secret cisco
ALS2(config)# line vty 0 15
ALS2(config-line)# password cisco
ALS2(config-line)# login
ALS2(config-line)# end

2. By default, how many lines are available for telnet on the access switches?...