2.3.2.6 Packet Tracer – Configuring PAP and CHAP Authentication

Last Updated on May 3, 2018 by Admin

2.3.2.6 Packet Tracer – Configuring PAP and CHAP Authentication

Packet Tracer – Configuring PAP and CHAP Authentication (Answer Version)

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

Topology

Addressing Table

Device	Interface	IP Address	Subnet Mask	Default Gateway
R1	G0/0	192.168.10.1	255.255.255.0	N/A
	S0/0/0	10.1.1.1	255.255.255.252	N/A
R2	G0/0	192.168.30.1	255.255.255.0	N/A
	S0/0/1	10.2.2.2	255.255.255.252	N/A
R3	S0/0/0	10.1.1.2	255.255.255.252	N/A
	S0/0/1	10.2.2.1	255.255.255.252	N/A
	S0/1/0	209.165.200.225	255.255.255.252	N/A
ISP	S0/0/0	209.165.200.226	255.255.255.252	N/A
	G0/0	209.165.200.1	255.255.255.252	N/A
Web	NIC	209.165.200.2	255.255.255.252	209.165.200.1
PC	NIC	192.168.10.10	255.255.255.0	192.168.10.1
Laptop	NIC	192.168.30.10	255.255.255.0	192.168.30.1

Objectives

Part 1: Review Routing Configurations

Part 2: Configure PPP as the Encapsulation Method

Part 3: Configure PPP Authentication

Background

In this activity, you will practice configuring PPP encapsulation on serial links. You will also configure PPP PAP authentication and PPP CHAP authentication.

Part 1: Review Routing Configurations

Step 1: View running configurations on all routers.

While reviewing the router configurations, note the use of both static and dynamic routes in the topology.

Step 2: Test connectivity between computers and the web server.

From PC and Laptop, ping the web server at 209.165.200.2. Both ping commands should be successful. Remember to give enough time for STP and EIGRP to converge.

Part 2: Configure PPP as the Encapsulation Method

Step 1: Configure R1 to use PPP encapsulation with R3.

Enter the following commands on R1:

R1(config)# interface s0/0/0
R1(config-if)# encapsulation ppp

Step 2: Configure R2 to use PPP encapsulation with R3.

Enter the appropriate commands on R2:

R2(config)# interface s0/0/1
R2(config-if)# encapsulation ppp

Step 3: Configure R3 to use PPP encapsulation with R1, R2, and ISP.

Enter the appropriate commands on R3:

R3(config)# interface s0/0/0
R3(config-if)# encapsulation ppp
R3(config)# interface s0/0/1
R3(config-if)# encapsulation ppp
R3(config)# interface s0/1/0
R3(config-if)# encapsulation ppp

Step 4: Configure ISP to use PPP encapsulation with R3.

a. Click the Internet cloud, then ISP. Enter the following commands:

Router(config)# interface s0/0/0
Router(config-if)# encapsulation ppp

b. Exit the Internet cloud by clicking Back in the upper left corner or by pressing Alt+left arrow.

Step 5: Test connectivity to the web server.

PC and Laptop should be able to ping the web server at 209.165.200.2. This may take some time as interfaces start working again and EIGRP reconverges.

Part 3: Configure PPP Authentication

Step 1: Configure PPP PAP Authentication Between R1 and R3.

Note: Instead of using the keyword password as shown in the curriculum, you will use the keyword secret to provide a better encryption of the password.

a. Enter the following commands into R1:

R1(config)# username R3 secret class
R1(config)# interface s0/0/0
R1(config-if)# ppp authentication pap
R1(config-if)# ppp pap sent-username R1 password cisco

b. Enter the following commands into R3:

R3(config)# username R1 secret cisco
R3(config)# interface s0/0/0
R3(config-if)# ppp authentication pap
R3(config-if)# ppp pap sent-username R3 password class

Step 2: Configure PPP PAP Authentication Between R2 and R3.

Repeat step 1 to configure authentication between R2 and R3 changing the usernames as needed. Note that each password sent on each serial port matches the password expected by the opposite router.

R2(config-if)# username R3 secret class
R2(config)# interface s0/0/1
R2(config-if)# ppp authentication pap
R2(config-if)# ppp pap sent-username R2 password cisco

R3(config-if)# username R2 secret cisco
R3(config)# interface s0/0/1
R3(config-if)# ppp authentication pap
R3(config-if)# ppp pap sent-username R3 password class

Step 3: Configure PPP CHAP Authentication Between R3 and ISP.

a. Enter the following commands into ISP. The hostname is sent as the username:

Router(config)# hostname ISP
ISP(config)# username R3 secret cisco
ISP(config)# interface s0/0/0
ISP(config-if)# ppp authentication chap

b. Enter the following commands into R3. The passwords must match for CHAP authentication:

R3(config)# username ISP secret cisco
R3(config)# interface serial0/1/0
R3(config-if)# ppp authentication chap

Step 4: Test connectivity between computers and the web server.

From PC and Laptop, ping the web server at 209.165.200.2. Both ping commands should be successful. Remember to give enough time for STP and EIGRP to converge.