Answers and Explanations
A1: Answers: A, B, and D. A is correct because VLANs can segment stations logically by function or team. B is correct because flexibility is added; users can be grouped by department, cross-functional product teams, or other grouping definitions you choose. D is correct; security is provided because members of one VLAN do not see the traffic on another VLAN. C is incorrect; there is no logging inherent to VLANs.

A2: Answer: B. VLANs are logical broadcast domains, defined by the administrator, and can span multiple physical subnets. A is incorrect because VLANs are logical broadcast domains, not physical. C is incorrect because VLANs span multiple physical subnets, not logical subnets. D is incorrect because VLANs create logical broadcast domains, not physical domains.

A3: Answer: D. VLANs are supported on switches. A is incorrect, as bridges do not support VLANs. B is incorrect because VLANs are not implemented on routers. C is incorrect, as hubs do not provide support for VLANs.

A4: Answer: B. A trunk provides capability for a VLAN to span across multiple switches because it can carry traffic for multiple VLANs. A is incorrect because port spanning is not the technology used to carry traffic for multiple VLANs. C is incorrect because fast Ethernet is a version of Ethernet that can operate at 100Mbps. D is incorrect because split horizon helps prevent routing loops by not sending route information out the interface that received it.

A5: Answers: C and D. C is correct because static mode refers to port assignments configured manually by an administrator. D is correct because dynamic port configuration is supported as well, when using a VLAN Management Policy Server. A is incorrect; there is no public membership mode. B is incorrect, as there is no private VLAN membership mode.

A6: Answers: C and D. The Catalyst 5000 series can be configured as a VMPS, and the 6509 can be configured as a VMPS. A is incorrect, as the Catalyst 1924 does not support configuration as a VMPS. B is incorrect, as the Catalyst 2950 also does not support configuration as a VMPS.

A7: Answer: C. The source MAC address of the sending station is used to assign a port to a specific VLAN. A is incorrect because the source IP address is irrelevant to the server. B is incorrect, as the hostname of the source device is not used to assign VLANs. D is incorrect because the source port of the traffic is not a consideration when assigning VLANs.

A8: Answers: C and D. When a Catalyst switch receives a frame on a dynamic port, it queries the VMPS. The VMPS then checks its database, which contains mappings of MAC addresses to VLANs. A is incorrect because a dynamic port can belong to only one VLAN at a time. B is incorrect because multiple hosts from different VLANs cannot all be active on a dynamic port.

A9: Answers: A and C. The 802.1Q protocol is an IEEE standard, nonproprietary method to implement trunking, and ISL is a proprietary Cisco protocol for implementing trunking. B is incorrect, as WEP is used to secure wireless networks. D is incorrect because IEEE 1394 (also known as FireWire) is a PC communications port.

A10: Answer: B. In 802.1Q trunking, the identifier value of the native VLAN is VLAN 1. A is incorrect because VLAN 1 is the default VLAN, not VLAN 0. C is incorrect because the default VLAN identifier is numerical. D is incorrect, as there is a default VLAN ID (VLAN 1).

A11: Answers: B and D. The 802.1Q protocol doesn't tag native VLAN frames, and tagged frames cannot be read by ordinary stations. A is incorrect because native VLAN frames are not tagged. C is incorrect because the information added when a frame is tagged renders it unreadable by ordinary stations.

A12: Answer: D. Adding a tag recomputes the frame check sequence. A is incorrect because the destination of the frame remains unchanged. B is incorrect, as the source of the frame does not change. C is incorrect because the data remains unchanged.

A13: Answers: B, C, and D. ISL supports full-duplex and half-duplex, and trunking is supported to allow VLAN information among different switches. A is incorrect because ISL is proprietary to Cisco. E is incorrect because ISL does not provide encryption. F is incorrect because ISL does not provide authentication.

A14: Answer: B. ISL functions at Layer 2, the Data-link layer of the OSI Model. A, C, and D are incorrect because ISL does not function at those layers of the OSI Model.

A15: Answer: A. The CRC ensures the frame has not been damaged in transit. B is incorrect because a digital signature is not used by ISL. C is not correct, because even though the idea of data integrity is to ensure that data is not modified, it does not specifically address the question. D is incorrect; Bridge Protocol Data Units indicate whether the frame is a spanning-tree BPDU.

A16: Answer: B. VTP functions at Layer 2, the Data-link layer of the OSI Model. A, C, and D are incorrect because VTP does not function at those layers of the OSI Model.

A17: Answer: D. The primary function of VTP is messaging, to ensure VLAN configuration consistency and the management of additions, deletions, and name changes. C is incorrect. VTP does manage deletions; however, it is not the sole, primary function of VTP. A and B are incorrect because encryption and authentication are not features of VTP.

A18: Answer: A. A switch can be in only a single VTP domain. B, C, and D are incorrect, as a switch cannot belong to 64, 255, or an unlimited number of domains.

A19: Answers: A, B, and D. Server mode is one of three VTP modes of operation; Client mode is a VTP mode of operation that does not allow creation, modification, or deletion of VLANs; and although Transparent mode acts much like Server mode, it does not synchronize information. C, E, and F are incorrect because Peer, Static, and Dynamic are not VTP modes.

A20: Answer: A. Server mode is one of three VTP modes of operation, and is the default. B is incorrect, because although Client mode is a VTP mode of operation that doesn't allow the creation, modification, or deletion of VLANs, it is not the default. D is incorrect, because although Transparent mode acts much like Server mode, it does not synchronize information and is not the default. C, E, and F are not VTP modes.

A21: Answer: B. NVRAM is used to store VLAN configurations, not RAM or flash memory. D is incorrect; configurations are stored in NVRAM in case of a power failure.

A22: Answer: B. Client mode forwards advertisements and synchronizes information. It does not save information in NVRAM. A is incorrect, as Server mode is a VTP mode that creates, modifies, and deletes VLANs. It forwards advertisements it receives, synchronizes information, and saves configuration information in NVRAM. D is incorrect, as Transparent mode creates, modifies, and deletes VLANs, and it forwards advertisements and saves configurations in NVRAM, but it does not synchronize. C, E, and F are not VTP modes.

A23: Answers: A and D. Server mode is a VTP mode that creates, modifies, and deletes VLANs. It forwards advertisements it receives, synchronizes information, and saves configuration information in NVRAM. D is correct because Transparent mode creates, modifies, and deletes VLANs. B is incorrect; Client mode forwards advertisements and synchronizes information, but it does not save information in NVRAM. C, E, and F are not VTP modes.

A24: Answers: A, B, and D. Server mode is a VTP mode that creates, modifies, and deletes VLANs. It forwards advertisements it receives and synchronizes information. It saves configuration information in NVRAM. Client mode forwards advertisements and synchronizes information. It does not save information in NVRAM. Finally, Transparent mode creates, modifies, and deletes VLANs. C, E, and F are incorrect because they are not VTP modes.

A25: Answer: D. Transparent mode creates, modifies, and deletes VLANs. It forwards advertisements and saves configurations in NVRAM. It does not synchronize, however. A is incorrect because Server mode is a VTP mode that creates, modifies, and deletes VLANs, forwards advertisements it receives, synchronizes information, and saves configuration information in NVRAM. B is incorrect because Client mode forwards advertisements and synchronizes information but does not save information in NVRAM. C, E, and F are not VTP modes.

A26: Answer: C. VTP advertisements are flooded through the management domain every five minutes by default. Answers A, B, and D are not the default settings.

A27: Answer: C. VTP uses multicast to send advertisements in the management domain. A is incorrect because broadcasts are not used for the propagation of advertisements. B is incorrect because unicasts are not as efficient for sending advertisements as multicast. D is incorrect, as there is no such method in VTP.

A28: Answer: C. The delete VTP command resets the configuration revision number. A, B, and D are invalid commands.

A29: Answer: D. Conflicts are resolved through revision numbers, and the higher revision number is processed. A is incorrect because order of reception is not a controlling factor. B is incorrect; the last advertisement is processed only if it has a higher revision number. C is incorrect because time stamps are not used.

A30: Answer: D. VTP pruning is the process of reducing unnecessary flooded traffic. A is incorrect because flood detection is not a valid method. B and C are incorrect, as broadcast quenching and flood quenching are not valid processes.

A31: Answer: A. Server mode is one of three VTP modes of operation, and is the default. It supports VTP pruning. B is incorrect, as Client mode is a VTP mode of operation that does not allow the creation, modification, or deletion of VLANs, and it doesn't support pruning. D is incorrect, because although Transparent mode acts much like Server mode, it does not synchronize information, and it doesn't support pruning. C, E, and F are not VTP modes.

A32: Answer: D. There is no default VTP domain set. A is incorrect because VLAN1 is simply the management VLAN. B and C are invalid.

A33: Answer: C. VTP domains on a Catalyst 2950 are created in VLAN Configuration mode. A is incorrect, because even as Privileged EXEC mode is required, you must enter the VLAN database command to get to VLAN Configuration mode. B is incorrect because this is valid only for Catalyst 1900 switches, which are now end of life. D is incorrect because no configuration changes can be made in User EXEC mode.

A34: Answer: C. The correct syntax on a Catalyst 5000 switch is set trunk desirable. A is incorrect, as this is the improper syntax for this switch; however, it is correct for a Catalyst 1900 series switch. B is incorrect, as this command does not achieve the desired effect. D is incorrect, as this command results in an error.

A35: Answer: C. Trunk ports are defined in Interface Configuration mode. A is incorrect, because even though Privileged EXEC mode is required, you must then enter Interface Configuration mode. B is incorrect; from Global Configuration mode, you must enter Interface Configuration mode. D is incorrect because no configuration changes are made in User EXEC mode.

A36: Answer: C. The vtp pruning enable command enables pruning on the switch. A and D are incorrect, as these commands result in an error message. B is incorrect because this is an invalid IOS command.

A37: Answer: B. The correct syntax is vtp domain name—in this case, vtp domain cisco01. A and C are incorrect because they are invalid syntax. D is incorrect, as this command is invalid.

A38: Answer: C. The switchport mode trunk command sets the port as a trunk port for 802.1Q traffic. This command is used in Interface Configuration mode. A is incorrect because this command results in an error message. B and D are not valid IOS commands.

A39: Answers: A and C. Interswitch Link and IEEE 802.1q are protocols that help define VLAN traffic over a single link. B is incorrect because VTP is merely a management protocol that helps to propagate VLANs to switches that belong to the same domain. D is incorrect because 802.1d is the IEEE standard for Spanning-Tree Protocol.

A40: Answer: A. You are configuring a port interface, so Interface Configuration mode is required. B is incorrect because there is no such Interface Configuration mode. C is incorrect because this is an interface, not a global setting; thus, Global Configuration mode is not appropriate. D is incorrect because Line Configuration mode is not the correct mode.

A41: Answer: D. A switch must be in VTP Server mode to propagate VLAN information to other switches. A is incorrect, as VTP pruning doesn't stop VTP revisions from propagating; it merely stops broadcasts from going to switches that do not have ports belonging to the VLANs that have the broadcasts. B is incorrect, as the VTP version number doesn't affect the propagation of advertisements. C is incorrect, as clients are unable to create VLANs.

A42: Answer: D. The exact maximum number of VLANs supported is switch-dependent. A, B, and C are incorrect because they are fixed numbers and not switch-dependent.

A43: Answer: A. You go to the particular interface/port you want to assign to VLAN 5 and enter the command switchport access vlan (vlan#). B is incorrect because it is an invalid command. C is incorrect because this assigns a port to a VLAN on a 1900 series switch, not the 2950. D is incorrect because it is an invalid command.

A44: Answer: B. A VLAN is considered its own broadcast domain. It helps contain broadcasts in a networked environment. A is incorrect because a VLAN actually segments the network even more. C is incorrect because VLANs are separate subnets that allow for Access-Lists to be applied, providing greater security. D is incorrect because Quality of Service can harness the power of VLANs to increase its functionality.

A45: Answer: C. The show vtp status command displays the requested information. A is incorrect; this command is valid but does not show the requested information. B is incorrect, as this command is valid for a 1900 series switch. D is incorrect because show ports is an invalid command.

A46: Answer: A. The show spantree command displays the requested information most effectively. B is incorrect because this command is not valid. C and D are valid commands but do not show the requested information.

A47: Answer: B. The no vlan command followed by the VLAN ID is the proper syntax. A is incorrect because this is an invalid IOS command. C is incorrect, and this command results in an error. D is incorrect, as this is not the proper syntax for the requested task.

A48: Answer: A. VLAN Configuration mode is used on Catalyst 2950 switches. B is incorrect; this command is entered in Global Configuration mode on a 1900 series switch. C and D are incorrect, as they are not the proper configuration modes.

A49: Answer: A. The router can route between the different subnets for the VLANs. It also can run ISL or 802.1q. B is incorrect because a Layer 2 switch has no Layer 3 comprehension. C is incorrect because a Hub is merely a multiport repeater with no capabilities to pass traffic between subnets. D is incorrect because there is no such device.

A50: Answer: B. The show vlan brief command displays the required information. A, C, and D are incorrect, as these are invalid IOS commands.