Lab Objective:

The objective of this lab exercise is for you to learn and understand how to create and troubleshoot IPv4 addresses on Cisco routers.

Lab Purpose:

Configuring IPv4 addressing is one of your most fundamental tasks as a Cisco engineer. In the exam, you may also be asked to troubleshoot IPv4 addressing that has already been configured but incorrectly, so you need to know which show commands to use.

Certification Level:

This lab is suitable for CCENT certification exam preparation.

Lab Difficulty:

This lab has a difficulty rating of 2/10.

Readiness Assessment:

When you are ready for your certification exam, you should complete this lab in no more than 10 minutes.

Lab Topology:

Please use the following topology to complete this lab exercise:

Task 1:

Configure the hostnames on routers R1 and R3 as illustrated in the topology.

Task 2:

Configure R1 S0/0, which is a DCE, to provide a clock rate of 768 Kbps to R3 (unless you are using GNS3). Configure the IP addresses on the Serial interfaces of R1 and R3 as illustrated in the topology. Configure the Loopback interfaces specified in the diagram on R1 and R3.

Task 3:

Use the correct show commands to check:

1. The summary of all configured IP addresses;
2. The status of the interface (up/down or administratively down); and
3. The subnet mask applied to the interface.

Configuration and Verification

Task 1:

Router#config t 
Enter configuration commands, one per line.  End with CTRL/Z. 
Router(config)#hostname R1 

Router#config t 
Enter configuration commands, one per line. End with CTRL/Z. 
Router(config)#hostname R3 
R3(config)#

Task 2:

R1(config)#interface s0/0
R1(config-if)#ip add 172.16.1.1 255.255.255.192
R1(config-if)#no shut 

R3(config)#interface s0/0
R3(config-if)#ip add 172.16.1.2 255.255.255.192
R3(config-if)#no shut 
R3(config)#interface lo10
R3(config-if)#ip add 10.10.10.3 255.255.255.128
R3(config)#interface lo20
R3(config-if)#ip add 10.20.20.3 255.255.255.240
R3(config)#interface lo30
R3(config-if)#ip add 10.30.30.3 255.255.255.248

Task 3:

R3#show ip int brie
Interface        IP-Address  OK? Method Status                Protocol
FastEthernet0/0  unassigned  YES unset  administratively down down
Serial0/0        172.16.1.2  YES manual up                    up      
Loopback10       10.10.10.3  YES manual up                    up      
Loopback20       10.20.20.3  YES manual up                    up     
Loopback30       10.30.30.3   ES manual up                    up 

R3#show interface s0/0 
Serial0/0 is up, line protocol is up
 Hardware is GT96K Serial
 Internet address is 172.16.1.2/26
 MTU 1500 bytes, BW 1544 Kbit/sec, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 
 Encapsulation HDLC, loopback not set