Lab 9.4.2 Troubleshooting WAN and PPP Connectivity
Step 1: Connect the equipment
Connect the equipment as shown in the topology diagram.
Step 2: Load the preconfiguration on R1
- See your instructor for obtaining the preconfigurations for this lab. Instructor note: The preconfigurations and final configurations can be found at the end of this lab.
- Connect PC1 to the console port of Router 1 to perform loading the preconfigurations using a terminal emulation program.
- Transfer the configuration from PC1 to Router 1:
1) In the terminal emulation program on PC1, choose Transfer > Send Text File.
2) Locate the preconfiguration file and choose Open to start the transfer of the preconfiguration to
Step 3: Load the preconfiguration on R2
Copy the preconfiguration on R2 using the process detailed in Step 2.
Step 4: Troubleshoot R1
a. Enter the command show interfaces serial 0/0/0 to view the details of the interface.
b. If any errors were found, make the necessary configuration changes to R1.
Step 5: Show the details of Serial interface 0/0/0 on R2
a. Enter the command show interface serial 0/0/0 to view the details of the interface.
b. If any errors were found, make the necessary configuration changes to R2.
Step 6: Turn on PPP debugging
a. Turn on the PPP debug function on both routers by entering debug ppp authentication at the
privileged EXEC mode prompt.
b. Turn off the debug function by entering undebug all at the privileged EXEC mode prompt of both
routers.
Step 7: Show the details of the configuration on R2
a. Enter the command show run to view the details of the interface.
b. If any errors were found, make the necessary configuration changes to R2.
R2(config-if)#ppp authentication chap
Step 8: Verify that the serial connection is functioning
a. Ping from R1 to R2 to verify that there is connectivity between the two routers.
b. If the answer for either question is no, troubleshoot the router configurations to find the error. Then do
the pings again until the answer to both questions is yes.
Step 9: Reflection
- The IP address and subnet mask for R1 s0/0/0 is 196.168.15.1 and 255.255.255.252. R2s s0/0/0 interface was misconfigured to 192.168.15.2 and an incorrect subnet mask of 255.255.255.254. If all PPP authentication and all other parameters were configured correctly would R1 have been able to ping R2? Why or why not? Jawaban : No, there are only two hosts possible with a subnet mask of 255.255.255.254. There is only one host bit left and both are invalid as host addresses.
- What command allows you to view the details of a specific interface? Jawaban : Show interface serial 0/0/0 or whichever interface you desire.
- When should you use the debug function in a router? Jawaban : when you want to troubleshoot or to view what is occurring in real-time on the network. Caution should be used so as to minimize the negative impact debugging has on network performance.
- What is the default serial encapsulation on a Cisco router? Jawaban : HDLC
