Chapter 10 Labs

Troubleshoot a Serial Connection 2 You have an SFO router and an LAX router connected in a back-to-back configuration as shown in the diagram. The current configuration has one or more problems. The routers should have the following configuration: Addresses on the 10.0.0.68/30 network are used for the serial connection. The clock rate should be set to 56000. HDLC encapsulation is used. In this lab, your task is to: Use the following commands to diagnose the problem:show ip interfaceshow interfacesshow controllers Correct any issues you find. When you're finished, the status of each interface should be up, and you should be able to ping each router from the other router interface.

Explore SFO. Select SFO. Press Enter to get started. At the SFO> prompt, type enable and press Enter. At the SFO# prompt, type show ip interface brief and press Enter to verify the configuration of the Serial0/1/0 interface. The status indicates a Layer 2 problem with the serial link. A Layer 2 problem is typically caused by a mismatched encapsulation type. At the SFO# prompt, type show interfaces s0/1/0 and press Enter. Notice that the encapsulation for this SFO is set to PPP. Explore LAX. Select LAX. Press Enter to get started. At the LAX> prompt, type enable and press Enter. At the LAX# prompt, type show interfaces s0/1/1 and press Enter. Notice that the encapsulation for SFO is set to HDLC. On SFO, configure the Serial0/1/0 interface to use HDLC as follows: At the SFO# prompt, type conf t and press Enter. At the SFO(config)# prompt, type int s0/1/0 and press Enter. At the SFO(config-if)# prompt, type encapsulation hdlc and press Enter. Press Ctrl + Z. At the SFO# prompt, type show interfaces s0/1/0 and press Enter to verify that HDLC encapsulation is being used. At the SFO# prompt, type ping 10.0.0.73 and press Enter to verify connectivity with the LAX Serial0/1/1 interface. A failed ping test indicates a Layer 3 problem. Verify the following TCP/IP configuration on both routers: At the SFO# prompt, type show interfaces and press Enter. At the LAX# prompt, type show interfaces and press Enter. Make sure both interfaces are assigned an IP address. Make sure both interfaces are using the same subnet mask. Make sure the IP address assigned to both interfaces is on the same subnet. On LAX, assign the IP address 10.0.0.70/30 to the s0/1/1 interface. At the LAX# prompt, type conf t and press Enter. At the LAX(config)# prompt, type int s0/1/1 and press Enter. At the LAX(config-if)# prompt, type ip address 10.0.0.70 255.255.255.252 and press Enter. Press Ctrl + Z. From both routers, verify that you can ping the other router. At the LAX# prompt, type ping 10.0.0.69 and press Enter. At the SFO# prompt, type ping 10.0.0.70 and press Enter.

Configure Back-to-Back Routers You have just connected two routers through their serial ports in a back-to-back configuration. You've already configured IP addresses on the Fa0/0 and Fa0/1 interfaces for both routers and have configured a static route on each router for the networks accessible through the other router. You need to complete the configuration by configuring the serial link between the two routers. Remember that a 30-bit mask has a magic number of 4. Valid subnets are 192.168.2.0, 192.168.2.4, 192.168.2.8, etc. The seventh subnet is 192.168.2.24. The first valid address on that subnet is 192.168.2.25. The last valid address on that subnet is 192.168.2.26. A 30-bit mask uses a mask value of 255.255.255.252. In this lab, your task is to: Assign an IP address to each serial interface. Use the seventh subnet on network 192.168.2.0 using a 30-bit mask:For S0/0/0 on RouterA, assign the first address on the subnet.For S0/0/1 on RouterB, assign the last address on the subnet. Use the show controllers command to identify the DCE device. On the DCE interface, configure a clock rate of 9600 using the clock rate command. Bring both interfaces up. Save the changes on both routers.

Find the DCE interface. Select RouterA. Press Enter to get started. At the RouterA> prompt, type show controllers s0/0/0 and press Enter. Select RouterB. Press Enter to get started. At the RouterB> prompt, type show controllers s0/0/1 and press Enter. RouterB has the DCE interface. Configure RouterB. At the RouterB> prompt, type enable and press Enter. At the RouterB# prompt, type config t and press Enter. At the RouterB(config)# prompt, type interface s0/0/1 and press Enter. At the RouterB(config-if)# prompt, type ip address 192.168.2.26 255.255.255.252 and press Enter. At the RouterB(config-if)# prompt, type clock rate 9600 and press Enter. At the RouterB(config-if)# prompt, type no shutdown and press Enter. Press Ctrl + Z. At the RouterB# prompt, type copy run start and press Enter. Press Enter to begin building the configuration. Configure RouterA. At the RouterA> prompt, type enable and press Enter. At the RouterA# prompt, type config t and press Enter. At the RouterA(config)# prompt, type interface s0/0/0 and press Enter. At the RouterA(config-if)# prompt, type ip address 192.168.2.25 255.255.255.252 and press Enter. At the RouterA(config-if)# prompt, type no shutdown and press Enter. Press Ctrl + Z. At the RouterA# prompt, type copy run start and press Enter. Press Enter to begin building the configuration.

View Serial Interface Status You're working with a single active router connected to four other routers through serial interfaces. You need to gather information about the serial connections between the routers. In this lab, your task is to answer the following questions using the CLI: What is the bandwidth of s0/0/0? Which interface is shut down? Which interface has a Layer 1 problem? Which interface is a DCE interface? Which interface is not assigned an IP address?

In the top right corner, select Answer Questions. Select Router to open the CLI. Press Enter to get started. At the prompt, type enable and press Enter to go to privileged mode. Type show interface and press Enter. Answer Questions 1-2. Type show ip interface brief and press Enter. Answer Question3. Type show controllers and press Enter to configure the enable password. Answer Question 4. Type show interface and press Enter.

Configure Static NAT You have a single router connected to the internet through its Serial0/0/0 interface. The router is used to create a screened subnet. Internal hosts accessible through the Fa0/0 interface should be able to be contacted by other hosts on the internet. You want to use NAT to translate the inside local address to an inside global address. In this lab, your task is to: Configure Fa0/0 interface as an inside NAT interfaces. Configure Serial0/0/0 interface as a outside NAT interfaces. Use the ip nat inside source static command to configure four static NAT mappings to map an inside local address to an inside global address as follows:ServerInside Local AddressInside Global AddressWeb server192.168.1.220.11.15.65DNS server192.168.1.320.11.15.66FTP server192.168.1.420.11.15.67Mail server192.168.1.520.11.15.68 Save your changes to the startup-config file.

Select Router. Press Enter to get started. At the Router> prompt, type enable and press Enter. At the Router# prompt, type config t and press Enter. At the Router(config)# prompt, type int fa0/0 and press Enter. At the Router(config-if)# prompt, type ip nat inside and press Enter. At the Router(config-if)# prompt, type int s0/0/0 and press Enter. At the Router(config-if)# prompt, type ip nat outside and press Enter. At the Router(config-if)# prompt, type ip nat inside source static 192.168.1.2 20.11.15.65 and press Enter. At the Router(config)# prompt, type ip nat inside source static 192.168.1.3 20.11.15.66 and press Enter. At the Router(config)# prompt, type ip nat inside source static 192.168.1.4 20.11.15.67 and press Enter. At the Router(config)# prompt, type ip nat inside source static 192.168.1.5 20.11.15.68 and press Enter. Press Ctrl + Z. At the Router# prompt, type copy run start and press Enter. Press Enter to begin building the configuration.

Configure Port Address Translation (PAT) You have a small network connected to the internet as shown in the diagram. Previously, you've used private addressing for your network. Now you'd like to use NAT to share a single IP address for all hosts on the private network. In this lab, your task is to: Change the IP address assigned on the Fa0/0 interface to use the last address in the 172.16.0.0/24 subnet. This changes the inside network to use private addressing. Designate Fa0/0 as a NAT inside interface. Designate Serial0/0/0 as a NAT outside interface. Create a standard access list number 1 that permits all source addresses on the 172.16.0.0/24 network. Use the ip nat inside source command to configure NAT to use the access list number 1 and the Serial0/0/0 interface. Include the overload parameter. This configures NAT to translate all inside host addresses on the 172.16.0.0/24 network to the public IP address assigned to the Serial0/0/0 interface. Save your changes to the startup-config file.

Select Router. Press Enter to get started. At the Router> prompt, type enable and press Enter. At the Router# prompt, type config t and press Enter. At the Router(config)# prompt, type interface fa0/0 and press Enter. At the Router(config)# prompt, type ip address 172.16.0.254 255.255.255.0 and press Enter. At the Router(config-if)# prompt, type ip nat inside and press Enter. At the Router(config-if)# prompt, type interface s0/0/0 and press Enter. At the Router(config-if)# prompt, type ip nat outside and press Enter. At the Router(config-if)# prompt, type exit and press Enter. At the Router(config)# prompt, type access-list 1 permit 172.16.0.0 0.0.0.255 and press Enter. At the Router(config)# prompt, type ip nat inside source list 1 interface s0/0/0 overload and press Enter. Press Ctrl + Z. At the Router# prompt, type copy run start and press Enter. Press Enter to begin building the configuration.

Troubleshoot a Serial Connection 1 You have two routers connected in a back-to-back configuration as shown in the diagram. The current configuration has one or more problems. The routers should have the following configuration: Addresses on the 10.0.0.68/30 network are used for the serial connection. The clock rate should be set to 56000. In this lab, your task is to: Use the following commands to diagnose the problem:show ip interfaceshow interfacesshow controllers Correct any issues you find. When you're finished, the status of each interface should be up, and you should be able to ping each router from the other router interface.

Troubleshoot SFO. Select SFO. Press Enter to get started. At the SFO> prompt, type enable and press Enter. At the SFO# prompt, type show ip interface brief and press Enter to verify the configuration of the Serial0/1/0 interface. The status indicates a Layer 1 problem with the serial link. A Layer 1 problem can be caused by: A disconnected cable. A missing clock rate. The device on the other end turning off or shutting down. At the SFO# prompt, type show controllers s0/1/0 and press Enter to see which interface is the DCE interface. The output (DTE V.35) indicates that Serial0/1/0 is the DTE interface. Because the configuration on the SFO router appears to be correct, continue troubleshooting on the LAX router. Troubleshoot LAX. Select LAX. Press Enter to get started. At the LAX> prompt, type enable and press Enter. At the LAX# prompt, type show ip interface brief and press Enter. The status for Serial0/1/1 is administratively down. Take the necessary actions to correct the problem on the LAX router. At the LAX# prompt, type show interfaces s0/1/1 and press Enter to verify the configuration. Notice that the status is down. Verify that the encapsulation type is set correctly. At the LAX# prompt, type show controllers s0/1/1 and press Enter. The line DCE V.35, clock rate 0 indicates that the device is the DCE device, but the clock rate has not been set. At the LAX# prompt, type conf t and press Enter. At the LAX(config)# prompt, type int s0/1/1 and press Enter. At the LAX(config-if)# prompt, type clock rate 56000 and press Enter to configure the clock rate on the Serial0/1/1 interface. At the LAX(config-if)# prompt, type no shutdown and press Enter to bring the router up. Press Ctrl + Z. At the LAX# prompt, type show interfaces s0/1/1 and press Enter to verify the configuration. At the LAX# prompt, type ping 10.0.0.69 and press Enter to make sure that the two devices can communicate.