Ccna routing and Switching Complete Study Guide

Remember how to verify an ARP cache with IPv6.    The command 

show ipv6 neighbors

 

shows the IP-to-MAC-address resolution table on a Cisco router.

Remember to look at the statistics on a router and switch interface to determine  

problems.    You’ve got to be able to analyze interface statistics to find problems if they 

exist, and this includes speed and duplex settings, input queue drops, output queue drops, 

and input and output errors.

Understand what a native VLAN is and how to change it.    A native VLAN works with 

only 802.1q trunks and allows untagged traffic to traverse the trunk link. This is VLAN 

1 by default on all Cisco switches, but it can be changed for security reasons with the 

switchport native vlan 

vlan

 command.

Written Lab 20

You can find the answers to this lab in Appendix A, “Answers to Written Labs.”

Write the answers to the following questions:

1.

  If your IPv6 ARP cache shows an entry of INCMP, what does this mean?

---

876

 

Chapter 20 

■

  Troubleshooting IP, IPv6, and VLANs

2.

  You want traffic from VLAN 66 to traverse a trunked link untagged. Which command 

will you use?

3.

  What are the five modes you can set a switch port to?

4.

  You are having a network problem and have checked the cables to find out if there’s a 

faulty cable or interface in the mix and also verified the interface’s statistics, made sure 

that devices are determining the correct path from the source to the destination, and 

verified that you don’t need to manipulate the routing. What are your next trouble-

shooting steps?

5.

  You need to find out if the local IPv6 stack is working on a host. What command will 

you use? 

hands-on Labs for Troubleshooting

Please check 

www.lammle.com/ccna

 for the latest information and downloads available 

for studying when using my books. Preconfigured hands-on troubleshooting labs are 

available for download, with the answers to the troubleshooting problems found on my 

forum.

---

Review Questions 

877

Review Questions

The following questions are designed to test your understanding of this 

chapter’s material. For more information on how to get additional ques-

tions, please 

www.lammle.com/ccna

.

You can find the answers to these questions in Appendix B, “Answers to Review 

Questions.”

1.  You need to verify the IPv6 ARP cache on a router and see that the state of an entry is 

REACH. What does REACH mean?