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QUESTION 60
What would happen to a frame if a VLAN port configured as a trunk on the Catalyst switch CK1 were to receive an untagged frame?
A. The frame will cause an error message to be sent.
B. The frame will be dropped.
C. The frame will be processed as a native VLAN frame.
D. The frame will be tagged, and then processed as a native VLAN frame.
Correct Answer: C Section: (none) Explanation
Explanation/Reference:
Explanation:
On an IEEE 802.1Q trunk port, all transmitted and received frames are tagged except for those on the
VLAN configured as the native VLAN for the port. Frames on the native VLAN are always transmitted
untagged and are normally received untagged. The default native VLAN is VLAN 1.
Reference:
http://www.cisco.com/en/US/products/hw/optical/ps2006/
products_module_configuration_guide_chapter09186
a
QUESTION 61
Switch CK1 has a trunk link configured with IEEE 802.1Q encapsulation. What is the maximum Ethernet frame size on this trunk port?
A. 1496 Bytes
B. 1500 Bytes
C. 1518 Bytes
D. 1522 Bytes
E. 1548 Bytes
Correct Answer: D Section: (none) Explanation
Explanation/Reference:
Explanation:
The 802.1q tag is 4 bytes; hence the resulting ethernet frame can be as large as 1522 bytes (1518 for the
maximum Ethernet frame size plus the 4 byte 802.1Q tag). The minimum size of the Ethernet frame with
802.1q tagging is 68 bytes.
Reference:
http://www.cisco.com/en/US/tech/ CK3 89/ CK3 90/technologies_tech_note09186a0080094665.shtml
QUESTION 62
The original frame is encapsulated and an additional header is added before the frame is carried over a trunk link. At the receive end, the header is removed and the frame is forwarded to the assigned VLAN.
This describes which technology?
A. DISL
B. DTP
C. IEEE802.1Q
D. ISL
E. MPLS
Correct Answer: D Section: (none) Explanation
Explanation/Reference:
QUESTION 63
Assuming you have an IOS based switch; which command would you execute if you
wanted to specify IEEE 802.1Q encapsulation on a trunked port?
A. Switch(config-if)#switchport trunk encapsulation dot1q
B. Switch(config-if)#switchport encapsulation dot1q
C. Switch(config-if)#switchport trunk encapsulation isl
D. Switch(config)#switchport 0/1 trunk encapsulation isl
E. None of the above
Correct Answer: A Section: (none) Explanation
Explanation/Reference:
Explanation:
Ethernet Trunk Encapsulation Types:
1.
switchport trunk encapsulation isl – Specifies ISL encapsulation on the trunk link.
2.
switchport trunk encapsulation dot1q – Specifies 802.1Q encapsulation on the trunk link.
3.
switchport trunk encapsulation negotiate – Specifies that the interface negotiate with the neighboring interface to become an ISL (preferred) or 802.1Q trunk, depending on the configuration and capabilities of the neighboring interface. The trunking mode, the trunk encapsulation type, and the hardware capabilities of the two connected interfaces determine whether a link becomes an ISL or 802.1Q trunk. Reference: http://www.cisco.com/en/US/products/hw/switches/ps700/ products_configuration_guide_chapter09186a008007 f
QUESTION 64
Two Certkiller switches are connected as shown below:
Which statements are true regarding the configuration of the above pair of switches? (Select two)
A. The trunk is currently using the ISL trunking protocol.
B. The trunk is currently using the 802.1q trunking protocol.
C. By default, all VLANs will be transmitted across this trunk.
D. By default, Switch CK1 and Switch CK2 ‘s Fast Ethernet 0/1 port will not generate DTP messages.
E. By default, the trunk can only support one VLAN, and only that single VLAN is transmitted across the trunk.
Correct Answer: BC Section: (none) Explanation
Explanation/Reference:
Explanation:
The second line in each configuration (#switchport trunk encapsulation dot1q) proves that B is correct, as
dot1q is Cisco IOS for 802.1q trunking.
A trunk allows inter-VLAN traffic to flow between directly connected switches. By default, a trunk port is a
member of all VLANs, so traffic for any and all VLANs can travel across this trunk. That includes broadcast
traffic! Reference:
http://www.mcmcse.com/cisco/guides/trunking_and_trunking_protocols.shtml
QUESTION 65
Switches Certkiller 1 and Certkiller 2 are connected as shown in the diagram below:
Use the following output taken from each port Certkiller 1: show config: interface GigabitEthernet0/1 switchport trunk encapsulation dot1q switchport mode dynamic auto no ip address show interface gig0/1 switchport: Name: Gi0/1 Switchport: Enabled Administrative Mode: dynamic auto Operational Mode: down Administrative Trunking Encapsulation: dot1q Negotiation of Trunking: On Access Mode VLAN: 1 (default) Certkiller 2: show interface gig0/1 switchport: Name: Gi0/1 Switchport Enabled Administrative Mode: dynamic auto Operational Mode: down Administrative Trunking Encapsulation: dot1q Negotiation of Trunking: On Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) In accordance with the above exhibit: what’s preventing the two switches from trunking on the link between them?
A. There is no IP address denied.
B. no shutdown needs to be entered on the interfaces.
C. Both sides are in auto negotiation mode.
D. ISL should be used instead of 802.1q.
E. Access mode VLAN must be different from native mode VLAN.
Correct Answer: C Section: (none) Explanation
Explanation/Reference:
Explanation:
In the switchport mode command, you can set the trunking mode to any of the following:
1.
trunk-This setting places the port in permanent trunking mode. The corresponding
switch port at the other end of the trunk should be similarly configured because negotiation is not allowed. You should also manually configure the encapsulation mode.
2.
dynamic desirable (the default)-The port actively attempts to convert the link into
trunking mode. If the far-end switch port is configured to trunk, dynamic desirable, or dynamic auto mode,
trunking is successfully negotiated.
3.
dynamic auto-The port converts the link into trunking mode. If the far-end
switch port is configured to trunk or dynamic desirable, trunking is negotiated.
Because of the passive negotiation behavior, the link never becomes a trunk if both ends of the link are left
to the dynamic auto default.
QUESTION 66
You have just configured an ISL trunk line over Ethernet media between two Cisco Switches, each switch having identical modules, software revisions, and VLAN configurations. Which of the following variables are NOT necessary for the ISL trunk to operate properly? (Select all that apply)
A. Identical trunk negotiation parameters at each end of the link
B. Identical duplex at each end of the link
C. Identical speed at each end of the link
D. Identical native VLAN parameters at each end of the link
Correct Answer: AD Section: (none) Explanation
Explanation/Reference:
Explanation: In order for a trunk connection to function properly, it is not necessary for the trunking negotiation parameters to be identical. For example, one end could be configured as “on” and the other could be configured for “auto-negotiate” and the trunk would be operational. Similarly, it is not necessary for the native VLAN parameters to be the same at each end. Incorrect Answers: B, C: One of the requirements for trunking to work is to have both sides of the trunk agree on the speed and duplex settings. Both sides must be configured with identical speed and duplex settings.
QUESTION 67
An ISL trunk connects switches CK1 and CK2 . What is the numerical range of user-configurable ISL VLANs on these switches?
A. 1-1001
B. 0-4095
C. there is no range
D. 0 – 1000
E. None of the above
Correct Answer: A Section: (none) Explanation
Explanation/Reference:
Explanation: The valid range of user-configurable ISL VLANs is 1-1001. The valid range of VLANs specified in the IEEE 802.1Q standard is 0-4095. In a network environment with non-Cisco devices connected to Cisco switches through 802.1Q trunks, you must map 802.1Q VLAN numbers greater than 1000 to ISL VLAN numbers. 802.1Q VLANs in the range 1-1000 are automatically mapped to the corresponding ISL VLAN. 802.1Q VLAN numbers greater than 1000 must be mapped to an ISL VLAN in order to be recognized and forwarded by Cisco switches.
QUESTION 68
An ISL trunk connects switches CK1 and CK2 . What is true about the Inter-Switch Link (ISL) protocol? (Select two)
A. ISL can be used between Cisco and non-Cisco switch devices.
B. ISL calculates a new CRC field on top of the existing CRC field.
C. ISL adds 4 bytes of protocol-specific information to the original Ethernet frame.
D. ISL adds 30 bytes of protocol-specific information to the original Ethernet frame.
Correct Answer: BD Section: (none) Explanation
Explanation/Reference:
Explanation:
B: A second frame check sequence (FCS) field lies at the end of the frame.
D: ISL is an external tagging process: new 26-byte ISL header is added to the original Ethernet frame. A second 4-byte frame check sequence (FCS) field is added at the end of the frame so 30 bytes of total overhead is added. Incorrect Answers:
A: Cisco’s propriety version of frame tagging is ISL. ISL can only be used between Cisco routers.
C: 30 bytes are added to the Ethernet frame, not 4 bytes. 4 bytes are added using 802.1Q encapsulation.
QUESTION 69
Which of the commands below enables a trunking protocol that appends a four byte CRC to the packet when applied to the Certkiller switch?
A. Switch(config-if)#switchport trunk encapsulation dot1q
B. Switch(config-if)#switchport trunk encapsulation ietf
C. Switch(config-if)#switchport trunk encapsulation fddi
D. Switch(config-if)#switchport trunk encapsulation isl
E. None of the above
Correct Answer: D Section: (none) Explanation
Explanation/Reference:
Explanation: ISL is made up of three major components: a header, the original Ethernet frame, and a frame check sequence (FCS) at the end. With ISL, an Ethernet frame is encapsulated with a header that transports VLAN IDs between switches and routers. The 26-byte header containing a 10-bit VLAN ID is added to each frame. In addition, a 4-byte tail is added to the frame to perform a cyclic redundancy check (CRC). This CRC is in addition to any frame checking that the Ethernet frame performs. Reference: Building Cisco Multilayer Switched Networks (Cisco Press) page 99
QUESTION 70
Which statement is true regarding the configuration of ISL trunks?
A. All catalyst switches support ISL trunking.
B. A Catalyst switch will report giants if one side is configured for ISL while the other side is not.
C. ISL trunking requires that native VLANs match.
D. A Catalyst switch cannot have ISL and IEEE 802.1q trunks enabled.
E. None of the above
Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation:
The 802.1q tag is 4 bytes; hence the resulting ethernet frame can be as large as 1522 bytes. The minimum
size of the Ethernet frame with 802.1q tagging is 68 bytes. ISL frames are the standard MTU used in Ethernet frames, which is 1518 bytes. If one end of the trunk is configured for ISL frames of up to 1518 bytes will be expected on it, while the other end will be sending frames up to 1522 bytes in length. On the ISL configured end, these incoming frames will be considered as giants. This is just one of the reasons why ISL and 802.1Q are incompatible. Incorrect Answers:
A: Not every Cisco switch model supports ISL.
C: In ISL, it is not necessary for the native VLANs to match.
D: Although it is true that each end of a trunk should be configured using the same encapsulation types, it is possible for a switch to have an ISL trunk configured on one port and an 802.1Q trunk on another port.
QUESTION 71
Two Certkiller switches are connected via a trunk using VTP. Which VTP information does a Catalyst switch advertise on its trunk ports when using VTP? (Select two)
A. STP root status
B. VTP mode
C. Negotiation status
D. Management domain
E. Configuration revision number
Correct Answer: DE Section: (none) Explanation
Explanation/Reference:
Explanation:
The role of the VLAN Trunking Protocol (VTP) is to maintain VLAN configuration consistency across the
entire network. VTP is a messaging protocol that uses Layer 2 trunk frames to manage the addition,
deletion, and renaming of VLANs on a network-wide basis from a centralized switch that is in the VTP
server mode. VTP is responsible for synchronizing VLAN information within a VTP domain. This reduces
the need to configure the same VLAN information on each switch.
Using VTP, each Catalyst Family Switch advertises the following on its trunk ports:
1.
Management domain
2.
Configuration revision number
3.
Known VLANs and their specific parameters
QUESTION 72
You need to investigate a VTP problem between two Certkiller switches. The lack of which two prevents VTP information from propagating between switches? (Select two)
A. A root VTP server
B. A trunk port
C. VTP priority
D. VLAN 1
E. None of the above
Correct Answer: BD Section: (none) Explanation
Explanation/Reference:
Explanation: In Switch tow types of links are available, access and trunk. The interface is in access mode can carry the information of only one VLAN and trunk can carry the information of more than one VLAN. VTP carry the information of more than one vlan so Switch port should be in trunk mode. VLAN1 is the default VLAN on Cisco Switch, by default all interface belongs to VLAN 1.
QUESTION 73
CK1 and CK2 are switches that communicate via VTP. What is the default VTP advertisement intervals in Catalyst switches that are in server or client mode?
A. 30 seconds
B. 5 minutes
C. 1 minute
D. 10 seconds
E. 5 seconds
F. None of the above
Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation:
Periodic ( default is 5 minutes) VTP advertisements are sent out each trunk port with the multicast
destination MAC address 01-00-0C-CC-CC-CC. VTP advertisements contain the following configuration
information:
1.
VLAN IDs (ISL and 802.1Q)
2.
Emulated LAN names (ATM LANE)
3.
802.10 SAID values (FDDI)
4.
VTP domain name
5.
VTP configuration revision number
6.
VLAN configuration, including the maximum transmission unit (MTU) size for each VLAN
7.
Frame format
QUESTION 74
On the network shown below, VTP has been enabled on the trunk links between all switches within the TEST domain. An administrator has recently enabled VTP pruning. Port 1 on Switch Certkiller 1 and port 2 on Switch Certkiller 4 are assigned to VLAN 2. A broadcast is sent from the host connected to Switch Certkiller 1.
Where will the broadcast propagate?
A. Switches Certkiller 1, Certkiller 2 , and Certkiller 4 will receive the broadcast, but only Switch Certkiller 4 will forward it out port 2.
B. Only Switch Certkiller 4 will receive the broadcast and will forward it out port 2.
C. Every switch in the network receives the broadcast and will forward it out all ports.
D. Every switch in the network receives the broadcast, but only Switch Certkiller 4 will forward it out port 2.
Correct Answer: A Section: (none) Explanation
Explanation/Reference:
Explanation:
The default behavior of a switch is to propagate broadcast and unknown packets across the network. This
behavior results in a large amount of unnecessary traffic crossing the network.
VTP pruning increases bandwidth efficiency by reducing unnecessary flooding of traffic, such as
broadcast, multicast, unknown, and flooded unicast packets. VTP pruning increases available bandwidth
by restricting flooded traffic to those trunk links that the traffic must use to access the appropriate network
devices. By default, VTP pruning is disabled.
Enabling VTP pruning on a VTP server enables pruning for the entire management domain. VTP pruning
takes effect several seconds after it is enabled. By default, VLANs 2 through 1000 or 2 through 1001 are
pruning eligible, depending upon the platform.
VTP pruning does not prune traffic from VLANs that are pruning ineligible. VLAN 1 is always pruning
ineligible and VLAN 1 cannot be removed from a trunk. However, the “VLAN 1 disable on trunk” feature
available on Catalyst 4000, 5000, and 6000 family switches enables the pruning of user traffic, but not
protocol traffic such as CDP and VTP, for VLAN 1 from a trunk. Use the vtp pruning command to make
VLANs pruning eligible on a Cisco IOS-based switch. Switch(vlan)#vtp pruning Once pruning is enabled, use the switchport trunk pruning command to make a specific VLAN pruning ineligible. Switch(config)#interface fastethernet 0/3 Switch(config-if)#switchport trunk pruning vlan remove vlan 5
QUESTION 75
You want to configure switch CK1 to propagate VLAN information across the Certkiller network using VTP. What must be configured on a Cisco switch in order to advertise VLAN information?
A. VTP mode
B. VTP password
C. VTP revision number
D. VTP pruning
E. VTP domain name
F. None of the above
Correct Answer: E Section: (none) Explanation
Explanation/Reference:
Explanation: If the switch being installed is the first switch in the network, the management domain will need to be created. However, if the network has other switches running VTP, then the new switch will join an existing management domain. Verify the name of the management domain. If the management domain has been secured, verify and configure the password for the domain. To create a management domain or to add a switch to a management domain, use the vtp domain command in the global configuration mode or VLAN configuration mode. Switch(config)#vtp domain name Switch(vlan)#vtp domain
QUESTION 76
The Certkiller switches have all been upgraded to use VTP version 2. What are two benefits provided in VTP Version 2 that are not available in VTP Version 1? (Select two)
A. VTP version 2 supports Token Ring VLANs
B. VTP version 2 allows VLAN consistency checks
C. VTP version 2 allows active redundant links when used with spanning tree
D. VTP version 2 reduces the amount of configuration necessary
E. VTP version 2 saves VLAN configuration memory
Correct Answer: AB Section: (none) Explanation
Explanation/Reference:
Explanation: Understanding VTP Version 2 If you use VTP in your network, you must decide whether to use VTP version1 or version2. Note: If you are using VTP in a Token Ring environment, you must use version2. VTP version 2 supports the following features not supported in version1: Token Ring support-VTP version2 supports Token Ring LAN switching and VLANs (Token Ring Bridge Relay Function [TrBRF] and Token Ring Concentrator Relay Function [TrCRF]). Unrecognized Type-Length-Value (TLV) Support-A VTP server or client propagates configuration changes to its other trunks, even for TLVs it is not able to parse. The unrecognized TLV is saved in NVRAM. Version-Dependent Transparent Mode-In VTP version1, a VTP transparent network device inspects VTP messages for the domain name and version, and forwards a message only if the version and domain name match. Because only one domain is supported in the supervisor engine software, VTP version 2 forwards VTP messages in transparent mode without checking the version. Consistency Checks-In VTP version 2, VLAN consistency checks (such as VLAN names and values) are performed only when you enter new information through the CLI or SNMP. Consistency checks are not performed when new information is obtained from a VTP message, or when information is read from NVRAM. If the digest on a received VTP message is correct, its information is accepted without consistency checks. Reference: http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2ZY/configuration/guide/ vtp.html#wp1020
QUESTION 77
The Certkiller network administrator needs to enable VTP pruning within the Certkiller network. What action should a network administrator take to enable VTP pruning on an entire management domain?
A. Enable VTP pruning on any switch in the management domain
B. Enable VTP pruning on any client switch in the domain
C. Enable VTP pruning on a VTP server in the management domain
D. Enable VTP pruning on every switch in the domain
E. None of the above
Correct Answer: C Section: (none) Explanation
Explanation/Reference:
Explanation: The default behavior of a switch is to propagate broadcast and unknown packets across the network. This behavior results in a large amount of unnecessary traffic crossing the network. VTP pruning increases bandwidth efficiency by reducing unnecessary flooding of traffic, such as broadcast, multicast, unknown, and flooded unicast packets. VTP pruning increases available bandwidth by restricting flooded traffic to those trunk links that the traffic must use to access the appropriate network devices. By default, VTP pruning is disabled. Enabling VTP pruning on a VTP server enables pruning for the entire management domain. VTP pruning takes effect several seconds after it is enabled. By default, VLANs 2 through 1000 or 2 through 1001 are pruning eligible, depending upon the platform. VTP pruning does not prune traffic from VLANs that are pruning ineligible. VLAN 1 is always pruning ineligible and VLAN 1 cannot be removed from a trunk. However, the “VLAN 1 disable on trunk” feature available on Catalyst 4000, 5000, and 6000 family switches enables the pruning of user traffic, but not protocol traffic such as CDP and VTP, for VLAN 1 from a trunk. Use the vtp pruning command to make VLANs pruning eligible on a Cisco IOS-based switch. Switch(vlan)#vtp pruning Once pruning is enabled, use the switchport trunk pruning command to make a specific VLAN pruning ineligible. Switch(config)#interface fastethernet 0/3 Switch(config-if)#switchport trunk pruning vlan remove vlan 5
QUESTION 78
VTP is configured on switch CK1 . Which of the following features were added in VTP version 2 that were not previously supported in VTP version 1? (Select two)
A. Supports Token Ring VLANs.
B. Allows VLAN consistency checks.
C. Saves VLAN configuration memory.
D. Reduces the amount of configuration necessary.
E. Allows active redundant links when used with spanning tree.
Correct Answer: AB Section: (none) Explanation
Explanation/Reference:
Explanation:
VTP Version 2 includes the following improvements: Token Ring VLAN support, TLV support, transparent
mode, and Consistency checks.
Incorrect
Answers:
C, D: These were not improvements added to VTP Version 2.
E: STP detects and prevents loops by logically disabling the redundant path ports so there are no active redundant links.
QUESTION 79
The Certkiller switches are configured to use VTP. What’s true about the VLAN trunking protocol (VTP)? (Select two)
A. VTP messages will not be forwarded over nontrunk links.
B. VTP domain names need to be identical. However, case doesn’t matter.
C. A VTP enabled device which receives multiple advertisements will ignore advertisements with higher configuration revision numbers.
D. A device in “transparent” VTP v.1 mode will not forward VTP messages.
E. VTP pruning allows switches to prune VLANs that do not have any active ports associated with them.
Correct Answer: AD Section: (none) Explanation
Explanation/Reference:
Explanation:
VTP messages are only transmitted across trunk links.
If the receiving switch is in transparent mode, the configuration is not changed. Switches in transparent
mode do not participate in VTP. If you make VTP or VLAN configuration changes on a switch in
transparent mode, the changes are not propagated to the other switches in the network.
Incorrect
Answers:
B: The VTP domain name is case sensitive and it must be identical with the domain name configured on the VTP server.
C: This is incorrect because if a VTP client receives an advertisement with a higher revision number, it won’t ignore it. In fact, the advertisement with a higher revision level takes precedence when the switch is configured in client mode.
E: VTP pruning enhances network bandwidth use by reducing unnecessary flooded traffic, such as broadcast, multicast, unknown, and flooded unicast packets. VTP pruning increases available bandwidth by restricting flooded traffic to those trunk links that the traffic must use to access the appropriate network devices. It does not prune the individual VLANs.
QUESTION 80
Switch CK1 and CK2 both belong to the Certkiller VTP domain. What’s true about the switch operation in VTP domains? (Select all that apply)
A. A switch can only reside in one management domain
B. A switch is listening to VTP advertisements from their own domain only
C. A switch is listening to VTP advertisements from multi domains
D. A switch can reside in one or more domains
E. VTP is no longer supported on Catalyst switches
Correct Answer: AB Section: (none) Explanation
Explanation/Reference:
Explanation:
A VTP domain is made up of one or more interconnected devices that share the same VTP domain name.
A switch can be configured to be in only one VTP domain, and each VLAN has a name that is unique
within a management domain.
Typically, you use a VTP domain to ease administrative control of your network or to account for physical
boundaries within your network. However, you can set up as many or as few VTP domains as are
appropriate for your administrative needs. Consider that VTP is transmitted on all trunk connections,
including ISL, IEEE 802.1Q, 802.10, and LANE.
Switches can only belong to one management domain with common VLAN requirements, and they only
care about the neighbors in their own domains.
Reference: CCNP Switching Exam Certification Guide: David Hucaby & Tim Boyles, Cisco Press 2001,
ISBN 1-58720 000-7 page 114
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