VTP, RSTP, VLAN, PVSTP, 802.1q) (35 questions)
Section 9: Describe how VLANs create logically separate networks and the need for routing between them (10 questions)
QUESTION NO: 1
Which of the following a true statements regarding the use of VLANs to segment a network? (Select three)
A. They increase the size of collision domains B. They allow logical grouping of users by function.
C. They can enhance network security.
D. They increase the size of the broadcast domain while decreasing the number of collision domains.
E. They increase the number of broadcast domains while decreasing the size of the broadcast domains.
F. They simplify switch administration.
Answer: B, C, E Explanation:
VLANs are used to segment a LAN into multiple, smaller LANs. This can be used to enhance security as local traffic from one VLAN will not be passed to users in other VLANS.
Incorrect Answers:
A. VLANs are used to decrease the size of a collision domain, not increase it.
D. The opposite is true.
F. The default operation of a switch is to allow all traffic and to enable all ports in VLAN 1. The use of VLANs will increase the complexity of the switch environment, making for more difficult administration.
QUESTION NO: 2
You wish to segment your LAN into multiple broadcast domains. Which technology method should you implement in order to do this?
A. Transparent bridging B. Cut-through switching C. Fragment-free switches D. Virtual LANs
E. Store-and-forward switching F. None of the above
Answer: D Explanation:
The creation of VLANs in a switch will provide separate Broadcast domains. By default, all ports in a Catalyst switch belong to VLAN 1. By creating additional VLANs, the LAN will be logically segmented into separate broadcast domains.
Incorrect Answers
A. Transparent bridging is called Transparent because the endpoints devices do not need to know that the bridges exists. It will not play any role for creating separate broadcast domain
B, E. Both of these are switching methods.
C. This has nothing to do with the creation of multiple broadcast domains.
QUESTION NO: 3
TestKing has implemented the use of VLANs in their network. Which of the following are considered to be a benefit of VLANs? (Choose three)
A. They increase the size of collision domains.
B. They allow logical grouping of users by function.
C. They can enhance network security,
D. The increase the size of broadcast domains while decreasing the number of the broadcast domains.
E. The increase the number of broadcast domains while decreasing the size of the broadcast domains.
F. They simplify switch administration.
Answer: B, C, E Explanation:
There are many motivations for using VLANs, including these:
1. To group users by department, or by groups that work together, instead of by physical location. (B)
2. To reduce overhead by limiting the size of each broadcast domain (E)
3. To enforce better security by keeping sensitive devices on a separate VLAN (C) 4. To separate specialized traffic from mainstream traffic - for example, putting IP telephones on a separate VLAN form user PCs.
QUESTION NO: 4
What are some of the characteristics of a typical VLAN arrangement, found throughout the TestKing switched LAN? (Select all that apply)
A. VLANs logically divide a switch into multiple, independent switches at Layer 2.
B. Trunk links can carry traffic for multiple VLANs.
C. VLAN implementation significantly increases traffic due to added trunking information.
D. A VLAN can span multiple switches.
E. VLANs typically increase the number of switches needed F. VLANs typically decrease the number of switches needed
Answer: A, B, D Explanation:
VLANs give you the power of making virtual LAN networks to subdivide collision domains into smaller units of functionality, without being limited by physical location.
A is correct because that is the exact function of a VLAN. B is correct because trunk links are used to carry traffic for multiple VLANs. D is correct because a VLAN can and often does span across multiple switches. VTP makes this possible.
Incorrect Answers:
C. Although trunking information does indeed add some level of overhead, the overall traffic overhead is greatly reduced though the use of VLANs.
E, F. The number of total switches needed in a network is the result of the number of devices on the entire LAN that need to be connected. Whether VLANs are used or not will have little, if any, impact on the total number of switches needed in a LAN.
QUESTION NO: 5
How could the TestKing corporation benefit from using VLANs on their network?
(Select three answer choices.)
A. VLANs allow access to network services based on department, not physical location.
B. VLANs utilize packet filtering to enhance network security.
C. VLANs provide a low-latency, high bandwidth internetworking alternative.
D. VLANs provide a method of communication between IP addresses in large networks.
E. VLANs establish segmented broadcast domains in switched networks.
F. VLANs can greatly simplify adding, moving, or changing hosts on the network.
Answer: A, E, F Explanation:
VLANs establish broadcast domains in switched networks, so by virtue of having the option to create many efficient broadcast domains, congestion is reduced and network throughput is greatly enhanced. VLANs allow networks to be divided by department or resource needs, rather then by physical location. When people move departments, leave a department, or join a department, administration is easy and convenient with a few keystrokes.
Incorrect Answers:
B, D. These would be router functions at layer 3. Switches and VLANs operate at layer 2 of the OSI model.
C. The use of VLANs may actually increase the latency in some cases, as traffic from one VLAN to the other will need to be routed.
QUESTION NO: 6
Two VLANs are connected to a switch as follows:
In this TestKing network segment, hosts on the same VLAN can communicate with each other but are unable to communicate with hosts on different VLANs. What is needed to allow communication between these two TestKing VLANs?
A. A router with subinterfaces configured on the physical interface that is connected to the switch
B. A router with an IP address on the physical interface that is connected to the switch C. A switch with a trunk link that is configured between the switches
D. A switch with an access link that is configured between the switches E. None of the above
Answer: A
QUESTION NO: 7
You are working as a network technician at TestKing University, when you get a call from the Engineering Faculty. They're complaining that they're receiving obsolete information from the Business Faculty's network traffic broadcasts.
What can you do to contain the Business Faculty's broadcast while still keeping it connected to the internet and the enterprise services of the University? (Select all valid answer choices)
A. Use half and full-duplex Ethernet on the Engineering Department LAN B. Establish a VTP domain to minimize the obsolete traffic
C. Change the switch IP address of the switch
D. Create separate VLANs and subnets for the two departments and route between the two
E. Provide greater bandwidth to the Engineering Department LAN
F. Place the business department on a separate subnet and route between networks
Answer: D, F Explanation:
In order to prevent the broadcast and link level multicast traffic separated between the departments, they need to be isolated at layer two. This can be accomplished in two ways.
The first is to create separate VLANs and place each department into a different one. The second method would be to separate the two departments into two completely different networks, and route between them.
Incorrect Answers:
A. Mixing the use of half and full duplex will make no difference to the number of broadcasts sent.
B. Trunking is only useful in networks that already contain VLANs.
C. This will make no difference, as all users will still be contained within the same IP subnet.
E. The amount of bandwidth involved will not have any impact on the amount of broadcasts that are sent and received.
QUESTION NO: 8
Two TestKing switches are shown below:
The switches have been configured with static VLANs as shown. During testing, the network administrator notices that VLAN 20 on SwitchA has no connectivity with VLAN 30 on SwitchB. What should the network administrator do?
A. Configure the interconnected ports on SwitchA and SwitchB into access mode.
B. Connect the two switches with a straight-through cable.
C. Add a Layer 3 device to connect VLAN 20 and VLAN 30.
D. Configure the management VLAN with IP address.
E. Ensure that the VIP passwords match on both switches.
Answer: C Explanation:
Network devices in different VLANs cannot communicate with one another without a router to route traffic between the VLANs. In most network environments, VLANs are associated with individual networks or subnetworks.
For example, in an IP network, each subnetwork is mapped to an individual VLAN.
Configuring VLANs helps control the size of the broadcast domain and keeps local traffic local. However, when an end station in one VLAN needs to communicate with an end station in another VLAN, interVLAN communication is required. This communication is supported by interVLAN routing. You configure one or more routers to route traffic to the appropriate destination VLAN.
The diagram below shows a basic interVLAN routing topology. SwitchA is in VLAN 10 and SwitchB is in VLAN20. The router has an interface in each VLAN.
Basic InterVLAN Routing Topology:
When HostA in VLAN10 needs to communicate with HostB in VLAN10, it sends a packet addressed to that host. SwitchA forwards the packet directly to HostB, without sending it to the router.
When HostA sends a packet to HostC in VLAN20, SwitchA forwards the packet to the router, which receives the traffic on the VLAN10 interface. The router checks the routing table, determines the correct outgoing interface, and forwards the packet out the VLAN20 interface to SwitchB. SwitchB receives the packet and forwards it to HostC.
Reference:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat5000/rel_5_2/layer3/routing.htm#wp13354
QUESTION NO: 9
The TestKing network is displayed below:
Study the exhibit: the topology and the partial switch command output.
The internetwork shown in the exhibit is experiencing connectivity problems. Host TestKing1 is unable to ping Host TestKing2.
What needs to be done to enable these hosts to ping each other?
A. The gateway on Host TestKing1 needs to be changed.
B. The IP address on Host TestKing2 needs to be reconfigured.
C. VLAN2 must be named.
D. The Fa0/1 interface on the TestKingA switch must be configured as a trunk port.
E. Switch port Fa0/1 must be moved to a different VLAN.
Answer: D Explanation:
Interface FA0/1 should be in any case configured as a trunk port so that a router could switch packets between the VLANs. The IP addresses are acceptable, so no issues should be caused due this.
QUESTION NO: 10
A TestKing network is displayed below:
Host TestKingB in the diagram is experiencing connectivity problems. Further Testing reveals that it cannot ping the default gateway. Based on the information shown in the exhibit, what is the problem?
A. The IP address of TestKingB is on a different subnet than the default gateway.
B. The Fa0/1 interface on the switch is administratively shutdown.
C. The switch is connected to the wrong interface on the TestKing1 router.
D. The FastEthernet interface on the TestKing router is not configured for trunking.
E. The Fastethernet 0/0.2 interface on the TestKing1 router is configured for the wrong VLAN.
F. The FastEthernet interface of the TestKing1 router is configured with the wrong Ethernet encapsulation.
Answer: E Explanation:
Based on the output shown above, the Fa 0/0.2 interface should be in VLAN 32, which is the same VLAN that other devices in the 192.168.2.X/24 subnet belong to. Interface FA0/0.1 should be configured for VLAN 22, while FA0/0/2 should be configured for VLAN 32.