CCNA 640-802 Ver 22-09-2008 page13
QUESTION 121
Part of the Certkiller switched LAN is shown below:
Based on the information show above, which device will provide the spanning-tree designated port role for the Certkiller network segment that services the printers?
A. Switch Certkiller A
B. Hub Certkiller E
C. Switch Certkiller C
D. Switch Certkiller B
E. Switch Certkiller D
F. None of the switches will provide the designated port role
Answer: C
Explanation:
Designated port A designated port is one that has been determined as having the best (lowest) cost. A designated port will be marked as a forwarding port.
QUESTION 122
The Certkiller network administrator needs to a switch named CK1 to become the root bridge for a redundant path switched network. What can be done to ensure that CK1 will always assume the role as the root bridge?
A. Assign the switch a higher MAC address than the other switches in the network have
B. Establish a direct link from the switch to all other switches in the network
C. Configure the switch full-duplex operation and configure the other switches for half-duplex operation
D. Configure the switch so that it has lower priority than other switches in the network
E. None of the above
Answer: D
Explanation:
Switch having lowest bridge ID will become the root bridge. The bridge ID is how STP keeps track of all the switches in the network. It is determined by a combination of the bridge priority (32,768 by default on all Cisco switches) and the base MAC address. The bridge with the lowest bridge ID becomes the root bridge in the network. To elect the desired switch as a root bridge, set the bridge priority lowest than other switch.
QUESTION 123
Four Certkiller PCs connect to a single switch as shown below:
In the Certkiller network shown above, switch Certkiller 1 has just been restarted and has passed the POST routine. Host Certkiller A (the one on the left) sends its initial frame to Host Certkiller C. What is the first thing the switch will do as regards to populating the switching table?
A. Switch Certkiller 1 will add 192.168.23.12 to the switching table
B. Switch Certkiller 1 will add 192.168.23.4 to the switching table
C. Switch Certkiller 1 will add 000B.DB95.2EE9 to the switching table
D. Switch Certkiller 1 will add 000A.8A47.E612 to the switching table
E. None of the above
Answer: D
QUESTION 124
CK1 is a switch in the Certkiller network. Why will CK1 never learn the broadcast address?
A. Broadcast frames are never sent to switches
B. A broadcast frame is never forwarded by a switch
C. Broadcasts only use network layer addressing
D. A broadcast address will never be the source address of a frame
E. Broadcast addresses use an incorrect format for the switching table
F. None of the above
Answer: D
Explanation:
There are three different address types:
* Unicast : One source to One destination
* Broadcast: One source to multiple destination
* Multicast: One source to multiple destination joined to group On unicast or broadcast or multicast communication, the source address is always the unicast address but the destination address can be unicast, broadcast or multicast.
QUESTION 125
DRAG DROP
You work as a network technician at Certkiller .com. Your boss, Mrs. Certkiller, is interested in basic switch configurations. Match the IOS command with the appropriate purpose.
Answer:
Explanation:
enable : This command is used to enter into User Privileges Mode
configure terminal: This command is used to enter into global configuration mode
hostname : This command is used to set the hostname of switch
ip default-gateway : This command should enter should enter on global configuration mode to set default gateway of switch.
Interface vlan 1 : Enters into the vlan 1 SVI (Switched Virtual Interface) configuration mode, where you can enter vlan 1 SVI interface specific configuration
ip add x.x.x.x y.y.y.y : Use to assign the ip address on interface
no shutdown: Brings the interface on up state from administratively down state
QUESTION 126
A Certkiller LAN is displayed in the diagram below:
Host Certkiller B sends a frame to host Certkiller C. What will the switch do with the frame?
A. Drop the frame
B. Send the frame out all ports except port 0/2
C. Return the frame to host Certkiller B
D. Send an ARP request for host Certkiller C
E. Send an ICMP Host Unreachable message to Host Certkiller B
F. Record the destination MAC address in the switching table and send the frame directly to Host Certkiller C
Answer: B
Explanation:
QUESTION 127
The following was seen on a Certkiller switch.
Certkiller 1 receives the frame with the addressing shown. According to the command output shown in the exhibit, how will Certkiller 1 handle this frame?
A. It will forward the frame out port Fa0/3 only.
B. It will drop the frame.
C. It will flood the frame out all ports except Fa0/3.
D. It will flood the frame out all ports.
Answer: C
Explanation:
Switches learn the MAC addresses of PCs or workstation the are connected to their switch ports by examining the source address of frames that are received on that port. Machines may have been removed from a port ,turned off, or moved to another port on the same switch or a different switch. This could cause confusion in frame forwarding the MAC address entry is automatically discard or ages out after 300 seconds if there is not MAC address of destination host in MAC table, switch sends broadcast to all ports except the source to find out the destination host. In the output there is no MAC address of the given host so the switch will flood to all ports except the source port, which is port fa 0/3.
QUESTION 128
Refer to the topology and MAC address table shown in the exhibit:
Host Certkiller A sends a data frame to host Certkiller D. What will the Certkiller 1 switch do when it receives the frame from host A?
A. The Certkiller 1 switch will flood the frame out of all ports except for port Fa0/3.
B. The Certkiller 1 switch will discard the frame and send an error message back to host Certkiller A.
C. The Certkiller 1 switch will add the destination address of the frame to the MAC address table and forward the frame to host D.
D. The Certkiller 1 switch will add the source address and port to the MAC address table and forward the frame to host Certkiller D.
E. None of the above
Answer: D
Explanation:
When switch receives the data frame from the host not having the MAC address already in the MAC table, it will add the MAC address to the source port on the MAC address table and sends the data frame. If the switch already has the MAC address in it's table for the destination, as it is in this case, it will forward the frame directly to the destination port. If it was not already in it's MAC table, then they frame would have been flooded out all ports except for the port that it came from.
QUESTION 129
Switch Certkiller A receives the frame with the addressing shown in the exhibit.
According to the command output also shown in the exhibit, how will Switch Certkiller A handle this frame?
A. It will flood the frame out all ports except Fa0/3.
B. It will forward the frame out port Fa0/3 only.
C. It will flood the frame out all ports.
D. It will forward the frame out port Fa0/6 only.
E. It will drop the frame.
F. None of the above
Answer: D
Explanation:
When frame receives the frame, it checks the source address on MAC table if MAC address found in MAC table it tries to forward if not in MAC table adds the Address on MAC table. After checking the source address, it checks the destination address on MAC table, if MAC address found on MAC table it forwards to proper ports otherwise floods on all ports except the source port. In this case, the MAC address shown is already in the table so it will be forwarded directly.
QUESTION 130
Please study the exhibit shown below carefully.
Why does the switch have two MAC addresses assigned to the FastEthernet 0/1 port in the switch address table?
A. Either Host3 or Host4 has just had the NIC replaced.
B. Data from Host3 and Host4 has been received by switch port FastEthernet 0/1.
C. Host3 and Host4 are on two different VLANs.
D. Data from two of the devices connected to the switch has been sent to Host3.
E. None of the above
Answer: B
Explanation:
Switches learn the MAC addresses of PCs or workstations that are connected to their switch ports by examining the source address of frames that are received on that port. When more than one device is attached to a switch port, such as via the use of a hub as shown in this example, the switch will retain the MAC address of each of the known devices on that port.
Part of the Certkiller switched LAN is shown below:
Based on the information show above, which device will provide the spanning-tree designated port role for the Certkiller network segment that services the printers?
A. Switch Certkiller A
B. Hub Certkiller E
C. Switch Certkiller C
D. Switch Certkiller B
E. Switch Certkiller D
F. None of the switches will provide the designated port role
Answer: C
Explanation:
Designated port A designated port is one that has been determined as having the best (lowest) cost. A designated port will be marked as a forwarding port.
QUESTION 122
The Certkiller network administrator needs to a switch named CK1 to become the root bridge for a redundant path switched network. What can be done to ensure that CK1 will always assume the role as the root bridge?
A. Assign the switch a higher MAC address than the other switches in the network have
B. Establish a direct link from the switch to all other switches in the network
C. Configure the switch full-duplex operation and configure the other switches for half-duplex operation
D. Configure the switch so that it has lower priority than other switches in the network
E. None of the above
Answer: D
Explanation:
Switch having lowest bridge ID will become the root bridge. The bridge ID is how STP keeps track of all the switches in the network. It is determined by a combination of the bridge priority (32,768 by default on all Cisco switches) and the base MAC address. The bridge with the lowest bridge ID becomes the root bridge in the network. To elect the desired switch as a root bridge, set the bridge priority lowest than other switch.
QUESTION 123
Four Certkiller PCs connect to a single switch as shown below:
In the Certkiller network shown above, switch Certkiller 1 has just been restarted and has passed the POST routine. Host Certkiller A (the one on the left) sends its initial frame to Host Certkiller C. What is the first thing the switch will do as regards to populating the switching table?
A. Switch Certkiller 1 will add 192.168.23.12 to the switching table
B. Switch Certkiller 1 will add 192.168.23.4 to the switching table
C. Switch Certkiller 1 will add 000B.DB95.2EE9 to the switching table
D. Switch Certkiller 1 will add 000A.8A47.E612 to the switching table
E. None of the above
Answer: D
QUESTION 124
CK1 is a switch in the Certkiller network. Why will CK1 never learn the broadcast address?
A. Broadcast frames are never sent to switches
B. A broadcast frame is never forwarded by a switch
C. Broadcasts only use network layer addressing
D. A broadcast address will never be the source address of a frame
E. Broadcast addresses use an incorrect format for the switching table
F. None of the above
Answer: D
Explanation:
There are three different address types:
* Unicast : One source to One destination
* Broadcast: One source to multiple destination
* Multicast: One source to multiple destination joined to group On unicast or broadcast or multicast communication, the source address is always the unicast address but the destination address can be unicast, broadcast or multicast.
QUESTION 125
DRAG DROP
You work as a network technician at Certkiller .com. Your boss, Mrs. Certkiller, is interested in basic switch configurations. Match the IOS command with the appropriate purpose.
Answer:
Explanation:
enable : This command is used to enter into User Privileges Mode
configure terminal: This command is used to enter into global configuration mode
hostname : This command is used to set the hostname of switch
ip default-gateway : This command should enter should enter on global configuration mode to set default gateway of switch.
Interface vlan 1 : Enters into the vlan 1 SVI (Switched Virtual Interface) configuration mode, where you can enter vlan 1 SVI interface specific configuration
ip add x.x.x.x y.y.y.y : Use to assign the ip address on interface
no shutdown: Brings the interface on up state from administratively down state
QUESTION 126
A Certkiller LAN is displayed in the diagram below:
Host Certkiller B sends a frame to host Certkiller C. What will the switch do with the frame?
A. Drop the frame
B. Send the frame out all ports except port 0/2
C. Return the frame to host Certkiller B
D. Send an ARP request for host Certkiller C
E. Send an ICMP Host Unreachable message to Host Certkiller B
F. Record the destination MAC address in the switching table and send the frame directly to Host Certkiller C
Answer: B
Explanation:
QUESTION 127
The following was seen on a Certkiller switch.
Certkiller 1 receives the frame with the addressing shown. According to the command output shown in the exhibit, how will Certkiller 1 handle this frame?
A. It will forward the frame out port Fa0/3 only.
B. It will drop the frame.
C. It will flood the frame out all ports except Fa0/3.
D. It will flood the frame out all ports.
Answer: C
Explanation:
Switches learn the MAC addresses of PCs or workstation the are connected to their switch ports by examining the source address of frames that are received on that port. Machines may have been removed from a port ,turned off, or moved to another port on the same switch or a different switch. This could cause confusion in frame forwarding the MAC address entry is automatically discard or ages out after 300 seconds if there is not MAC address of destination host in MAC table, switch sends broadcast to all ports except the source to find out the destination host. In the output there is no MAC address of the given host so the switch will flood to all ports except the source port, which is port fa 0/3.
QUESTION 128
Refer to the topology and MAC address table shown in the exhibit:
Host Certkiller A sends a data frame to host Certkiller D. What will the Certkiller 1 switch do when it receives the frame from host A?
A. The Certkiller 1 switch will flood the frame out of all ports except for port Fa0/3.
B. The Certkiller 1 switch will discard the frame and send an error message back to host Certkiller A.
C. The Certkiller 1 switch will add the destination address of the frame to the MAC address table and forward the frame to host D.
D. The Certkiller 1 switch will add the source address and port to the MAC address table and forward the frame to host Certkiller D.
E. None of the above
Answer: D
Explanation:
When switch receives the data frame from the host not having the MAC address already in the MAC table, it will add the MAC address to the source port on the MAC address table and sends the data frame. If the switch already has the MAC address in it's table for the destination, as it is in this case, it will forward the frame directly to the destination port. If it was not already in it's MAC table, then they frame would have been flooded out all ports except for the port that it came from.
QUESTION 129
Switch Certkiller A receives the frame with the addressing shown in the exhibit.
According to the command output also shown in the exhibit, how will Switch Certkiller A handle this frame?
A. It will flood the frame out all ports except Fa0/3.
B. It will forward the frame out port Fa0/3 only.
C. It will flood the frame out all ports.
D. It will forward the frame out port Fa0/6 only.
E. It will drop the frame.
F. None of the above
Answer: D
Explanation:
When frame receives the frame, it checks the source address on MAC table if MAC address found in MAC table it tries to forward if not in MAC table adds the Address on MAC table. After checking the source address, it checks the destination address on MAC table, if MAC address found on MAC table it forwards to proper ports otherwise floods on all ports except the source port. In this case, the MAC address shown is already in the table so it will be forwarded directly.
QUESTION 130
Please study the exhibit shown below carefully.
Why does the switch have two MAC addresses assigned to the FastEthernet 0/1 port in the switch address table?
A. Either Host3 or Host4 has just had the NIC replaced.
B. Data from Host3 and Host4 has been received by switch port FastEthernet 0/1.
C. Host3 and Host4 are on two different VLANs.
D. Data from two of the devices connected to the switch has been sent to Host3.
E. None of the above
Answer: B
Explanation:
Switches learn the MAC addresses of PCs or workstations that are connected to their switch ports by examining the source address of frames that are received on that port. When more than one device is attached to a switch port, such as via the use of a hub as shown in this example, the switch will retain the MAC address of each of the known devices on that port.
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