This article will give you the opportunity to configure point-to-point links and few of the features associated with them. Before you go ahead and configure these, I advise you to go over this article from Intenseschool website: CCNA Prep: Point-to-Point WANs (link to http://resources.intenseschool.com/point-to-point-wans/).

Regarding the simulation, you have two files:

  • configuring_ppp_wan _init.pkt – contains the initial topology. The hosts don’t have connectivity between them and the OSPF adjacencies between the routers are down.
  • configuring_ppp_wan_final.pkt – this is the final configuration with what you should have configured. You can use this file to compare your configuration.

Regarding the topology, on the subnets where a PC is connected, the router’s interface has the IP address whose last octet is .1 and last octet of the PC’s IP address is .100. The default gateway of the PC is the router’s IP address.

For instance, on the subnet with PC_2: PC_2 has the IP address of 10.10.20.100/24 and R3’s interface IP address is 10.10.20.1/24.

Each router has a loopback address in the form of 1.1.1.X/32, where X is the router number. For instance, the loopback address of R3 is 1.1.1.3/32.

Also, each subnet between the routers is written on the topology and every router is using the last octet as its router number. For instance, on the subnet 10.10.12.0/24, R2 has 10.10.12.2/24 and R1 has 10.10.12.1/24.

All three routers are running OSPF in area 0 so that the end hosts will have connectivity between them.

But the interfaces between the routers are not configured. The tasks will be to configure them based on the requirements.

Once they are correctly configured, the OSPF adjacencies between the routers will be up and the two PCs will have connectivity between them.

If needed, use this information:

  • The username will be the hostname of the routers.
  • For PAP authentication, the password will be in the format of Rx_cisco, where x is the router number. For instance, the password of R2 will be R2_cisco.
  • For CHAP authentication, the password will be cisco.

<pTask 1 requirements

  1. Configure the interfaces between R1 and R2 with PPP encapsulation and the IP addresses specified on the diagram.
  2. Configure the interfaces between R2 and R3 with PPP encapsulation and the IP addresses specified on the diagram.
  3. Configure PAP authentication between R1 and R2 with R1 requesting R2 to authenticate.
  4. Configure CHAP authentication between R2 and R3.

Task 1 verification

  1. Use the command ‘show interface’ to confirm that PPP encapsulation is configured.
  2. On PC_1, find Desktop tab then select Command Prompt and issue a ping towards 10.10.20.100. The ping should be successful if the OSPF adjacencies between routers are up. The OSPF adjacencies will be up only if you have configured correctly the interfaces and the PPP authentication.

Task 1 hints

  1. Use the command ‘encapsulation ppp’ to change the encapsulation to PPP.
  2. Use the command ‘username R2 password 0 R2_cisco’ to configure the user on R1.
  3. Use the command ‘ppp authentication pap’ on R1 interface towards R2.
  4. Use the command ‘ppp pap sent-username R2 password R2_cisco’ on R2 to configure PAP authentication and send the expected user/pass by R1.
  5. Use the command ‘username R3 password 0 R3_cisco’ on R2 to configure the user/pass sent by R3.
  6. Use the command ‘ppp authentication chap’ on R2 to configure CHAP authentication.
  7. Use the command ‘username R2 password 0 R2_cisco’ on R3 to configure the user/pass sent by R2.
  8. Use the command ‘ppp authentication chap’ on R3 to configure CHAP authentication.

As you can see, configuring PPP is easy if you know exactly the steps needed. You can accomplish this by going through the resource referenced in the beginning of this article.