Ccna certification Practice Tests

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Appendix 

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  Answers to Practice Test Questions

 79.  C.  The command 

show interface fastethernet 0/15 switchport will show the 

operational mode, and if configured as a trunk, it will show the native VLAN. The 

command 

show running-config is incorrect, as it will show all the interfaces. The 

command 

show interface fastethernet 0/15 is incorrect as it will not show the 

native VLAN information. The command 

show switchport fastethernet 0/15 is 

incorrect.

 80.  A.  The command to change the native VLAN of a trunk to VLAN 999 is 

switchport 

trunk native vlan 999. The command native vlan 999 is incorrect. The command 

switchport native vlan 999 is incorrect. Negating the command with no switchport 

native vlan 1 and then configuring switchport native vlan 999 is incorrect.

 81.  B.  This error is normal if it is the first interface to be changed over to the new native 

VLAN since the other interface has not been changed yet. However, if the other interface 

was changed already and you received this error, then CDP is letting you know that the 

other side is mismatched. CDP must be running on both sides of the trunk; therefore, you 

would not see this error if it was disabled on either side. If the interfaces were running 

mismatched trunking protocols, a different error would be seen. The version of CDP on 

the other switch will not prompt the error of native VLAN mismatch.

 82.  D.  The problems will not be apparent since the trunk will still function for tagged traffic. 

However, any traffic that is not tagged will be directed to the opposite side’s native 

VLAN. So traffic expected for VLAN 1 will be directed to VLAN 10, and VLAN 10 

traffic will be directed to VLAN 1 when the traffic is not tagged. Both CDP and VTP will 

continue to function over the trunk link. The misconfiguration will not allow any more 

broadcasts than normal over the trunk to Switch B.

 83.  B.  Cisco Discovery Protocol (CDP) will alert you to a native VLAN mismatch. You 

will receive the error 

%CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch 

discovered…. When a trunk is configured, the native VLAN is always used for CDP 

exchanges. VLAN Trunk Protocol (VTP) helps reduce configuration and maintenance 

of VLANs on Cisco switches. Cisco Inter-Switch Link (ISL) is a proprietary protocol for 

trunking. The 802.1Q protocol is a trunking protocol developed by the IEEE.

 84.  C.  VLAN 1002 is reserved for use with an FDDI VLAN and not allowed for Ethernet 

traffic. All Ethernet traffic must be a VLAN between 1 to 1001. You cannot use 1002 to 

1005 because they are used for legacy applications. The native VLAN does not need to be 

VLAN 1. The native VLAN can be an extended VLAN; however, this is not the problem.

 85.  B.  Link Layer Discovery Protocol is an IEEE standard of 802.1ab. Most Cisco devices 

can perform LLDP, but it must be configured. The Cisco Discovery Protocol (CDP) is a 

proprietary protocol used to communicate neighbor devices’ identities and capabilities. 

The IEEE 802.1a and 802.1b protocols are defunct protocols used for LAN management.

 86.  D.  The command to turn off CDP globally on a switch is 

no cdp run. The command cdp 

disable is incorrect. The command no cdp enable is incorrect. The command no cdp is 

incorrect.

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Chapter 2: Network Access (Domain 2)