CCNA3 Chapter 6 Practice Test Answers
What is the problem with the network in the diagram?
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It is not possible for a router to have four FastEthernet ports.
The VLANs will not be able to communicate with each other.
The router is not needed because these VLANs can communicate
through the switch.
This design will not scale well if more VLANs are added.
Another VLAN is added to the network shown above, but the router does not
have a spare FastEthernet port. What would be the most economical
solution?
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Buy an extra module for the router to provide more FastEthernet ports.
Connect an extra router, link the two routers together and enable a
routing protocol between them.
Configure a trunk link on the switch and subinterfaces on one of
the router ports.
Use a cheap hub to connect all the VLANs to the same router interface.
A trunk link between a router and a switch is carrying traffic for six VLANs.
What is a potential problem?
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The VLANs are sharing the link’s bandwidth and this could create
a bottleneck.
The volume of VTP traffic on the link is likely to have an adverse effect
on the network’s performance.
The traffic for the different VLANs is likely to be confused as all the
traffic goes through the same physical router interface.
The maximum number of subinterfaces that can be configured on a
router port is five.
A switch is configured as follows:
SW(config)#int f0/1
SW(config-if)#switchport mode access
SW
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SW(config-if)#switchport access VLAN 3
SW(config-if)#description link to router f0/0
SW(config)#int f0/2
SW(config-if)#switchport mode access
SW(config-if)#switchport access VLAN 3
SW(config-if)#description link to router f0/1
SW(config)#int f0/3
SW(config-if)#switchport mode access
SW(config-if)#switchport access VLAN 3
SW(config-if)#description link to PC A
SW(config)#int f0/4
SW(config-if)#switchport mode access
SW(config-if)#switchport access VLAN 4
SW(config-if)#description link to PC B
Why is PC A unable to ping PC B?
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There needs to be a trunk link to the router in order for VLANs to
communicate with each other.
The no shutdown command has not been given on the switch
interfaces.
The router will not handle traffic to or from VLAN 4.
Interface f0/1 on the switch should be connected to interface f0/1 on
the router.
A router is to be added to the configuration shown in the diagram above. This
will allow communication between the different VLANs. How many fast
ethernet ports will the router need?
 None, serial ports must be used.
 One, since trunking can be used.
 Two, one connecting to each switch.
 Three, one for each VLAN.
 Six, one for each VLAN on each switch.
How many IP addresses must be configured on the router mentioned in the
previous question?
 None, because VLANs operate at layer two.
 One, because only one physical ports is needed.
 Two, one for each switch.
 Three, one for each VLAN.
SW
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Six, one for each VLAN on each switch.
Switchport 0/4 is on VLAN2, port 0/6 is on VLAN3, port 0/8 is on VLAN4.
Part of the router configuration is as follows:
Router(config)#interface fastethernet 0/1.2
Router(config-subif)#encapsulation dot1q 2
Router(config-subif)#ip address 192.168.1.0 255.255.255.240
Router(config)#interface fastethernet 0/1.3
Router(config-subif)#encapsulation dot1q 3
Router(config-subif)#ip address 192.168.1.33 255.255.255.240
Router(config-subif)# interface fastethernet 0/1.4
Router(config-subif)# encapsulation dot1q 4
Router(config-subif)#ip address 192.168.1.49 255.255.255.240
Which of the following host IP addresses are suitable? (Choose 2)
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Host A, 192.168.1.20
Host A, 192.168.1.32
Host B, 192.168.1.46
Host B, 192.168.1.47
Host C, 192.168.1.44
Host C, 192.168.1.60
Topology and configuration are the same as in the previous question. Host IP
addresses are set as follows:
Host A, 192.168.1.13
Host B, 192.168.1.50
Host C, 192.168.1.58
Which statements are true? (Choose all that apply)
 Host A can receive messages from host B
 Host A can receive messages from host C
 Host B can receive messages from host A
 Host C can receive messages from host A
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A router-on-a-stick is configured as follows:
R(config)#interface f0/1.2
R(config-subif)#encapsulation dot1q 20
R(config-subif)#ip add 172.18.0.1 255.255.255.128
R(config-subif)#interface f0/1.3
R(config-subif)#encapsulation dot1q 30
R(config-subif)#ip add 172.18.0.161 255.255.255.224
R(config-subif)#interface f0/1.4
R(config-subif)#encapsulation dot1q 40
R(config-subif)#ip add 172.18.0.193 255.255.255.224
R(config-subif)# interface f0/1
R(config-if)#no shutdown
The router receives a frame on physical interface f0/1. The destination IP
address is 172.18.0.120. What will the router do?
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Drop the frame because the IP address is not on a known network.
Send the frame out of interface f0/2.
Send the frame out of interface f0/1.2 tagged for VLAN 2.
Send the frame out of interface f0/1.2 tagged for VLAN 20.
Which is true of inter-VLAN routing using “router-on-a-stick”?
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Not every router is able to create subinterfaces for VLANs. It
depends on the IOS features.
It is possible if the switch uses IEE802.1Q tagging, but not if the switch
uses ISL.
The router has to be running a routing protocol that supports VLSM.
The configuration is simpler than if separate physical interfaces are
used, but the cabling is more complicated.
How are default gateways configured for inter-VLAN routing when “router-ona-stick” is used?
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SW
All PCs attached to the switch will share the same default gateway
since there is only one physical connection to the router.
PCs on different VLANs must be configured with different default
gateways.
PCs must be configured with the same default gateway as the switch.
The switch default gateway is the IP address of the physical interface
on the router.
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What is true about MAC addresses when “router-on-a-stick” is used for interVLAN routing?
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SW
Each subinterface on the router has its own MAC address.
Each default gateway at layer 3 is linked with a different MAC address
at layer 2.
Each physical Ethernet interface on the router has one MAC
address.
The MAC address of the router interface is not used when the interface
is configured for trunking.
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