Chapter 2 - LAN Switching Technologies Flashcards
- Which benefit to a LAN does a switch provide? A. Breaks up broadcast domains
B. Breaks up collision domains C. Forces full-duplex on all ports
D. Allows for a fast uplink port
- B. Switches break up collision domains by allowing full-duplex. Switches are set to auto-negotiate duplex and speed by default, and they do not force full-duplex.
- Where are MAC address tables stored?
A. Flash
B. CPU registers C. RAM
D. NVRAM
- C. MAC address tables, also called CAM tables, are always built and stored temporarily in RAM. When the switch is turned off or the clear command is issued, the table no longer exists.
- Which advantage(s) are gained using switches?
A. Low latency
B. Software switching C. High cost
D. All of the above
- A. Switches allow for low latency because frames are forwarded. They utilize ASIC hardware-based switching and have low cost.
- How do switches forward frames only to the destination computer?
A. Forward filter decisions based on the MAC address table B. Forward filter decisions based on the routing table
C. Flooding ports for the destination MAC address
D. Broadcasting for the MAC address
- A. Switches make forward/filter decisions based upon the MAC address to port association in the MAC address table.
- Which mechanism does a switch employ to stop switching loops?
A. Port channels
B. Spanning Tree Protocol C. Etherchannels
D. Trunks
- B. The mechanism that switches use for loop avoidance is STP, or Spanning Tree Protocol.
- How are MAC addresses learned and associated with the port? A. Destination MAC address learning
B. Source MAC address learning C. Port listen/learning
D. Frame type learning
- B. Switches learn MAC addresses by inspecting the frame’s source MAC address on the incoming port. They then associate the source MAC address with the port it came in on.
- Which command will allow you to see the MAC address table?
A. Switch#show mac
B. Switch#show mac address-table C. Switch#show cam table
D. Switch#show mac table
- B. The command to see the MAC address table is show mac address-table. However, on some 4000 and 6500 series switches, show cam dynamic will perform the same function.
- Which statement is true of an ARP request entering into a switch?
A. The source MAC address of the frame will be all Fs.
B. The destination MAC address of the frame will be all Fs.
C. The switch will only forward the ARP request to the port for the destination computer.
D. The switch will respond directly back with an ARP reply.
- B. The destination MAC address for broadcasts are always all Fs, such as ffff.ffff.ffff.
- Which command will display all connected ports on a switch and include descriptions?
A. Switch#show ports
B. Switch#show counters interfaces C. Switch#show interfaces counters
D. Switch#show interfaces status
- D. The show interfaces status command will display the port number, connected status, VLAN, duplex, speed, and type of interface.
- Which is a consequence of not using loop avoidance with layer 2 switching?
A. Duplicate unicast frames B. Broadcast storms
C. MAC address thrashing
D. All of the above
- D. When loop avoidance such as STP is not employed and loops exist, you will get duplicate unicast frames and broadcast storms. This will inevitably thrash the MAC address table and degrade bandwidth to nothing.
- What is the default MAC address aging time for dynamic entries on most switches?
A. 30seconds B. 60seconds C. 300seconds
D. 500seconds
- C. The default MAC address aging time for dynamic entries is 300 seconds, or 5 minutes.
- Which is a correct statement when hubs are replaced with switches? A. The replacement increases collision domains.
B. The replacement decreases collision domains. C. The replacement increases broadcast domains.
D. The replacement decreases broadcast domains.
- A. The replacement of hubs with switches increases collision domains and effectively increases bandwidth.
- Which command will show the number of entries in a MAC address table?
A. Switch#show mac address-table
B. Switch#show mac address-table count C. Switch#show mac count
D. Switch#show cam count
- B. The command to show the current MAC address entry count in the MAC address table is show mac address-table count. This command will also show the maximum number of entries the table can hold.
- When a switch receives a frame, what does it use to make a forwarding decision?
A. Destination MAC address in the frame B. Source MAC address in the frame
C. Source IP address in the frame
D. Destination IP address in the frame
- A. Forward filter decisions are made upon the destination MAC address in the frame.
- Which switching method checks the CRC as the frame is received by the switch?
A. Cut-through mode B. Frag-free mode
C. Store-and-forwardmode D. Fast switching
- C. Store-and-forward mode is the default mode for mode edge switching equipment. Store-and-forward receives the frame, calculates the CRC, and then makes a forwarding decision.
- Which statement is true about collision domains?
A. All computers in the collision domain have the potential to have a frame
collision.
B. All computers in the collision domain have the potential to receive layer 2 broadcast messages.
C. All computers in the collision domain have the potential to receive layer 3 broadcast messages.
D. All computers in the collision domain are set to 10 Mb/s full-duplex.
- A. A collision domain is defined as a group of computers that can potentially have a frame collision. Adding switches that can negotiate full-duplex and forward/filter fixes these issues.
25. Which switch mode operation reads only the first 64 bytes before making a switching decision? A. Cut-through mode B. Fragment-free mode C. Store-and-forwardmode D. Fast switching
- B. Fragment-free mode reads the first 64 bytes and deems the frame intact and forwardable. This is because most collisions that would create frame fragments happen within the first 64 bytes of a frame. This method of switching is often found on SOHO switching equipmen
26. Which protocol on the host machine allows for a mapping of IP to MAC address? A. MAC Address Resolution Protocol B. Address Resolution Protocol C. Reverse Address Resolution Protocol D. Internet Control Message Protocol
- B. Address Resolution Protocol (ARP) is used to map remote IPs on the current LAN to MAC addresses. It does this by broadcasting at layer 2 to all nodes for a response for the MAC address. Thus, it is a mapping of IP address to MAC address
30. Which protocol on the host machine allows for a mapping of MAC to IP address? A. MAC Address Resolution Protocol B. Address Resolution Protocol C. Reverse Address Resolution Protocol D. Internet Control Message Protocol
- C. Reverse Address Resolution Protocol (RARP) is used to map MAC addresses on the current LAN to IPs. BOOTP also uses this method to allocate an IP address via the MAC address. Thus, it is a mapping of MAC address to IP address.
- Which command would you use to reset the MAC address table for learned MAC addresses in a switch?
A. Switch#reset mac address-table
B. Switch#clear mac-address-table dynamic C. Switch#clear mac-address-table
D. Switch#clear mac table
- B. The command used to reset the MAC address table is clear mac-address-table dynamic.
- You need to see all of the MAC addresses associated with a single interface. Which command would you use?
A. Switch>show mac address-table interfaces fast 0/1 B. Switch>show address-table interfaces fast 0/1
C. Switch#show mac interfaces fast 0/1
D. Switch#show address-table fast 0/1
- A. The command to see all of the MAC addresses on a single interface is show mac address-table interfaces fast 0/1. This command can be entered in either privileged exec mode or user exec mode.
34. Which switch mode operation reads only the first 6 bytes before making a switching decision? A. Cut-through mode B. Frag-free mode C. Store-and-forwardmode D. Fast switching
- A. Cut-through mode copies the first 6 bytes after the preamble into memory and makes a switching decision on the destination MAC address. Many data center switches use this method of switching to provide low latency while assuming no collisions will exist.
- Which option describes latency in switching?
A. The delay between routing packets to the destination interface
B. The delay between switching the frame to the destination interface C. The delay in forward lookups to forward packets
D. The delay in forward lookups to forward frames
- B. Latency in switching is the total time it takes to forward an incoming frame to its destination interface. Latency of frame forwarding adversely affects total bandwidth.
- Which is attributed to lowering switch latency? A. The use of higher bandwidth connections
B. Multiple interfaces aggregated together C. Hardware-basedbridging(ASICs)
D. Spanning Tree Protocol
- C. Hardware-based bridging uses specialized application-specific integrated circuits (ASICs) to provide low latency in switching frames.
- What is the difference between a broadcast frame and a flooded frame?
A. A broadcast frame contains a destination MAC address beginning with ff:ff:ff. B. A flooded frame is a frame that is unknown in the MAC address table.
C. A broadcast frame and a flooded frame are the same.
D. Flooding of frames only occurs if there are switching loops.
- B. Flooding occurs only when the destination MAC address is not in the current MAC address table.
- What is the most accurate definition of wire speed with switching?
A. Switching between two ports can happen at wire speed.
B. The switch can process requests at the incoming speed of the connection.
C. The switch can process requests at the incoming and outgoing speed of the connection.
D. The switch can auto-negotiate between several different wire speeds.
- C. Wire speed is the switch’s ability to process packets both incoming and outgoing on the same port at wire speed. However, this is not the switch’s ability to switch at that speed; the speed of the switch is limited by its backplane bandwidth.
- Which is a function of a layer 2 switch?
A. Forwarding the date based upon logical addressing
B. Repeating the electrical signal to all ports
C. Learning the MAC address by examining the destination MAC addresses
D. Determining the forwarding interfaces based upon the destination MAC address and tables
- D. Switches learn MAC addresses based upon incoming ports and examination of the source MAC address. It will build a MAC address table for future lookups. It then determines forwarding interfaces based upon the destination MAC address contained in the frame.
- What is a reason a network administrator would segment a network with a switch? A. Create more broadcast domains.
B. Create isolation of ARP messages. C. Create less collision domains.
D. Isolate traffic between segments.
- D. A switch creates micro-segmentation, which in turns isolates traffic between two talking computers from other computers that are not part of the communications. This in turn increases bandwidth for the computers that are not part of the communications between the two talking computers.
- If a switch uses the store and forward method of switching and receives a frame in which its CRC is invalid, what will happen?
A. The switch will re-create the frame with a new CRC and correct the missing information.
B. The switch will drop the frame and wait for retransmission of a new frame.
C. The switch will send back a frame for retransmission of the frame.
D. The switch will store the frame until a new frame with a matching CRC is received.
- B. The store and forward method of switching allows the switch to receive the entire frame and calculate the CRC against the data contained in the frame. If the CRC does not match, the frame is dropped, and the sending node must retransmit after an expiry timer or upper-protocol timer times out
- What information is added to the MAC address table when a frame is received on an interface?
A. Destination MAC address of the frame and incoming port number B. Source MAC address of the frame and incoming port number
C. Destination MAC address of the frame and outgoing port number
D. Source MAC address of the frame and outgoing port number
- B. When a frame is received on an incoming port, both the incoming port and the source MAC address are added to the MAC address table and set with an aging timer.
- What is the maximum wire speed of a single port on a 48-port Gigabit Ethernet switch?
A. 1,000Mb/s B. 2 Gb/s
C. 48 Gb/s
D. 96Gb/s
- A. Wire speed of a single port on a 48-port gigabit switch would be 1 Gb/s, or 1,000 Mb/s
- You need to change the default mac address aging time on a switch to 400 seconds. Which command would you use?
A. Switch#set mac aging 400
B. Switch#mac aging-time 400 seconds
C. Switch#mac-address-table aging-time 400
D. Switch#mac address-aging 400
- C. MAC address aging time can be configured via the command mac-address-table aging-time 400. You can additionally specify a VLAN ID.
- Under which circumstance will a switch drop a frame?
A. If the destination MAC address of the frame is unknown in the MAC address
table
B. If the source MAC address of the frame is unknown in the MAC address table
C. If the frame is deemed to be corrupt via the CRC
D. If the destination MAC address exists in another switch’s MAC address table
- C. The only time a frame is dropped is when the cyclic redundancy check (CRC) calculated against the frame’s payload deems the frame corrupt. If the destination MAC address is not known, it will be flooded to all active ports on the switch, but it will not be dropped.
- In a layer 2 frame, where is the destination MAC address?
A. The destination MAC address is in the first 6 bytes after the preamble.
B. The destination MAC address is in the second 6 bytes after the preamble. C. The destination MAC address is the payload data.
D. The destination MAC address is found in the preamble.
- A. The 6-byte destination MAC address is after the preamble/SFD so that it can be read by the switch for forwarding.
- What is the significance of the preamble?
A. The preamble allows the switch to allocate a buffer.
B. The preamble allows the switch to sense collisions before data is transmitted.
C. The preamble allows the switch to sync timing for the receipt of information to follow.
D. The preamble allows the switch to read the sequence and acknowledge receipt of the frame.
- C. The preamble allows for the source computer to sync its timing of the physical media independent interface with the destination computer. It achieves this via an alternating 1 and 0 pattern at a specific frequency, depending on data transfer speed. The Start Frame Delimiter (SFD) has an extra bit to let the destination computer know anything that follows is data.
- How many bits is the OUI assigned by the IEEE? A. 6bits
B. 22 bits C. 24bits D. 48 bits
- C. The organizationally unique identifier, or OUI, is 24 bits, or the first 3 bytes of the MAC address.
- What function does the Frame Check Sequence (FCS) perform?
A. The FCS will error-correct data in a frame.
B. The FCS will detect errors in a frame’s data.
C. The FCS is used for acknowledgment of receipt of the frame.
D. BothAandB
- B. The Frame Check Sequence is a 4-byte cyclical redundancy check (CRC) calculation. Its only function is to detect erroneous frames; it will not correct data and contains no parity to do so.
- If the Individual/Group (I/G) bit is set to 1 in the OUI portion of the MAC address, which statement is true?
A. The MAC address is unique and governed by the IEEE. B. The MAC address is locally governed.
C. The MAC address is a broadcast or multicast.
D. The MAC address should always be broadcast.
- C. When the I/G bit is set, it means that the MAC address is intended to be a broadcast or multicast for a group of recipients
- If the Group/Local (G/L) bit is set to 1 in the OUI portion of the MAC address, which statement is true?
A. The MAC address is a unique computer and governed by the IEEE. B. The MAC address is locally governed.
C. The MAC address is a broadcast or multicast.
D. The MAC address should always be broadcast.
- B. When the G/L bit (sometimes referred to as the U/L bit) is set, it means that the MAC address is locally governed. This means that the user has manually set the MAC address
- Which is a reason that the Ethernet protocol uses physical addresses?
A. It creates a differentiation between layer 2 and layer 3 communications. B. It defines a logical address scheme for devices.
C. It uniquely identifies devices at layer 2.
D. It allows the node to decide if the device is remote or local.
- C. MAC addresses are physical addresses that are burned into every NIC card and network device. They are unique at the Data Link layer for direct communication purposes.
- What is the nominal MTU for LAN communications?
A. 1,500bytes B. 1,500bits C. 9,000bytes
D. 9,000bits
- A. The nominal MTU size is 1,500 bytes of data. It may also be advertised as 1,518 bytes, which is calculated from 1,500-bytes (payload) + 6 bytes (source MAC address) + 6 bytes (destination MAC address) + 2 bytes (type field) + 4 bytes (FCS) = 1,518 bytes. If 802.1Q VLAN tagging is being used, it can be advertised as 1,522 bytes to allow for 4 bytes for tagging. If ISL VLAN tagging is being used, ISL requires 30 bytes + 1,518 bytes = 1,548 bytes
- What is the 2-byte type field used for in an Ethernet frame?
A. It defines the data type contained within the frame.
B. It identifies the upper-layer protocol for the data contained within the frame. C. It is a calculation with the FCS to provide error detection.
D. It describes the length of data contained within the frame.
- B. The Ethernet type field is 2 bytes and it identifies at layer 2 which upper-layer protocol to send the data to. When IPv4 is used, the type field is 08-00. When IPv6 is used, the type field is 86-dd.
- What is the purpose of the State Frame Delimiter byte in a frame? A. It provides physical timing for the frame following.
B. It divides the data and the physical timing portion of the frame.
C. It provides a means for the receiving node to know when data begins.
D. It delimits the destination and source MAC address.
- C. The preamble is 7 bytes of alternating 1s and 0s at a frequency that matches the bandwidth of the link. It is important to note that the 1s and 0s pattern starts with a 1 and ends with a 0 for 7 bytes (10101010). The SFD has an extra lower bit signaling the end of timing and the start of data (10101011).
- You have just resolved a problem and now need to monitor the problem on the interface. How would you reset the error counts for a single interface?
A. Switch#reset counters interface fast 0/1 B. Switch#clear interface fast 0/1
C. Switch#clear counters interface fast 0/1
D. Switch#clear statistics interface fast 0/1
- C. In order to clear the counters for a single interface, you would use the command clear counters interface fast 0/1. After it’s entered, you will need to confirm clearing of the counters. Then you can monitor the solution provided on the interface.
- You have statically set an interface to 100 Mb/s full-duplex. However, the device you are plugging in will not work. Which command would you use to set speed and duplex back to auto-negotiate?
A. Switch(config-if)#speed auto Switch(config-if)#duplex auto
B. Switch(config-if)#speed autonegotiate Switch(config-if)#duplex autonegotiate
C. Switch(config-if)#switchport autonegotiate
D. Switch(config-if)#interface autonegotiate
- A. The commands to set the port back to auto-negotiation are speed auto and duplex auto. You can also negate the command with no speed and no duplex commands. Both methods will set auto-negotiation back on the port.
- You have auto-negotiation turned off on the node, but it is turned on at the switch’s interface connecting the node. The interface is a 10/100/1000 Mb/s interface and the node is 100 Mb/s full-duplex. What will the outcome be when you plug in the node?
A. The switch interface will be set to the 100 Mb/s full-duplex. B. The switch interface will be set to the 100 Mb/s half-duplex. C. The switch interface will be set to the 10 Mb/s full-duplex.
D. The switch interface will be set to the 10 Mb/s half-duplex.
- B. Cisco switches can auto-detect speed, so the speed sensed will be 100 Mb/s. However, if the switch cannot detect the speed, then it will fall back to 10 Mb/s. Duplex is decided upon bandwidth when IEEE auto-negotiation is turned off. If the speed is 10 Mb/s or 100 Mb/s, then the duplex will be half-duplex; otherwise it will be full-duplex on 1000 Mb/s links.
- You plug a 100 Mb/s hub into a switch. What is the expected outcome?
A. The switch interface will be set to the 100 Mb/s full-duplex.
B. The switch interface will be set to the 100 Mb/s half-duplex. C. The switch interface will be set to the 10 Mb/s full-duplex.
D. The switch interface will be set to the 10 Mb/s half-duplex.
- B. Hubs do not participate in IEEE negotiation, and therefore the speed will be detected. However, since duplex cannot be negotiated, 10 Mb/s and 100 Mb/s connections will be half-duplex and 1000 Mb/s connections will be full-duplex.
- You want to see a status of all speed and duplex negotiations for all interfaces. Which command would you use?
A. Switch#show run
B. Switch#show interfaces counters C. Switch#shower interfaces status
D. Switch#show counters interfaces
- C. The show interfaces status command will display the port number, description, connected status, VLAN, duplex, speed, and type of interface.
- You are trying to reprovision a switch in a different part of your network. However, you still see the old VLANs configured from the old network. How can you rectify the problem?
A. Upgrade the IOS.
B. Typeerasestartup-config,confirmit,andreload. C. Typeclearvlan,confirmit,andreload.
D. Deletethevlan.dat,confirmit,andreload.
- D. The vlan.dat is the database for VLANs configured on a switch either manually or through VTP. It is persistent even if config.text (startup-config) is deleted. You must manually delete the vlan.dat.
- Which VLAN is the default VLAN used to configure all switches from the factory?
A. VLAN999 B. VLAN1002 C. VLAN1005
D. VLAN1
- D. All switches are configured by default with all interfaces in VLAN 1. This simplifies configuration if the switch is to be used as a direct replacement for a hub since nothing needs to be configured.
- What is the normal range for VLANs before you must use extended VLAN IDs?
A. VLAN 1 through 1001 B. VLAN 1 through 1002 C. VLAN 1 through 1005 D. VLAN 2 through 1002
- A. The normal VLAN range is 1 through 1001 before you must use the extended VLAN range.
- Which is a benefit to converting a network from a flat layer 2 network to a routed layer 3 VLAN-enabled network?
A. Increased collision domains for increased bandwidth B. Reduced complexity of design and operations
C. Flexibility of user management and design
D. Decreased number of broadcast domains for increased bandwidth
- C. The flexibility of design for workgroups of people and the ongoing management of moving and adding people is a benefit of a routed VLAN-enabled network.
- You have created a VLAN for the Research department. Now you need to configure an interface on the switch for the newly created VLAN. Which command will configure the interface for the respective VLAN?
A. Switch(config-if)#switchport vlan research
B. Switch(config-if)#switchport access vlan research C. Switch(config-if)#switchport access vlan 9
D. Switch(config-if)#switchport vlan 9
- C. When you’re configuring an interface for a VLAN, only the VLAN number can be used. The correct command is switchport access vlan 9.
- You are installing a VoIP phone on the same interface as an existing computer.
Which command will allow the VoIP phone to switch traffic onto its respective VLAN? A. Switch(config-if)#switchport voice vlan 4
B. Switch(config-if)#switchport vlan voice 4 C. Switch(config-if)#switchport voip vlan 4
D. Switch(config-if)#switchport access vlan 4 voice
- A. The switchport voice vlan 4 command will configure the interface to switch traffic with a COS value of 5 set by the phone to the voice VLAN of 4.
- Which type of port removes the VLAN ID from the frame before it egresses the interface?
A. Access port B. Trunk port C. Voice port
D. Native port
- A. All VLAN tagging is removed from the frame before it egresses an access port to the end device.
- You want to delete VLAN 1 for security reasons. However, the switch will not let you. What is the reason you cannot delete VLAN 1?
A. The VLAN is still configured on a port.
B. The VLAN serves as the switch’s main management IP. C. The VLAN is protected from deletion.
D. The VLAN is still configured as a native VLAN on a trunk.
- C. VLANs 1 and 1002 through 1005 are protected by the IOS and cannot be changed, renamed, or deleted.
- Which is a true statement about extended VLANs?
A. You cannot configure extended VLANs until the normal VLANs are all used. B. VTP versions 1 and 2 require the switch to be in transparent mode.
C. Extended VLANs are saved in the VLAN database.
D. Extended VLANs can only be used for FDDI.
- B. By default, the VTP mode is server. VTP v1 and v2 do not support storage and propagation of extended VLANs. However, when the switch is put into transparent mode, it does not participate in VTP, so the VLANs can be configured
- What is the extended VLAN range?
A. VLAN 1002 to 4096 B. VLAN 1006 to 4096 C. VLAN 1006 to 4094 D. VLAN 1006 to 4092
- C. The extended VLAN range is VLAN 1006 to 4094.
- Why is it recommended that you do not use VLAN 1?
A. It is not a production VLAN. B. It cannot be routed via an SVI.
C. It cannot participate in VTP transfers.
D. It shouldn’t be used for security reasons.
- D. For security concerns, it should not be used in production. It is the default VLAN configured on all switches. Potentially, a computer can be plugged into an interface defaulted to VLAN 1 and expose resources such as the switch management network.
- You need to create a VLAN to support jumbo frames. Which commands would configure jumbo frame support on a VLAN?
A. Switch#vlan 10 Switch(config-vlan)#mtu 9128
B. Switch(config)#vlan 10 Switch(config-vlan)#mtu 9128
C. Switch(config)#vlan 10 Switch(config-vlan)#jumbo frames
D. Switch(config)#vlan 10 Switch(config-vlan)#mtu 1548
- B. Configuration of jumbo frames requires creation of the VLAN from a global configuration prompt and then setting the maximum transmission unit (MTU). The value of the MTU will differ from switch to switch but is usually 9,000 bytes or higher
- What is the command to verify a VLAN and the port(s) it is associated with? A. Switch#show vlans
B. Switch#show vlan
C. Switch#show access vlan
D. Switch#show vlan database
- B. The command to verify that a VLAN is created and the port(s) it is associated with is show vlan.
- Which command(s) will delete a VLAN?
A. Switch(config)#vlan database Switch(config-vlan)#no vlan 9
B. Switch(config)#vlan database Switch(config-vlan)#delete vlan 9
C. Switch(config)#no vlan 9
D. Switch(config)#vlan 9 delete
- C. The command to delete VLAN 9 is no vlan 9 performed from a global configuration prompt.
- Which is a correct statement about frame and VLANs?
A. Broadcast frames are sent to ports that are configured in different VLANs.
B. Unicast frames that are not in the MAC address table are flooded to all ports in all VLANs.
C. The ports that link switches together must be access links.
D. Frames with a destination MAC that are not in the MAC address table are flooded to only ports in the respective VLAN.
- D. Frames with MAC addresses that are not in the MAC address table are flooded only to the ports in the respective VLAN
- A VLAN is not configured yet, but you mistakenly configure it on an interface via
the command switch access vlan 12. What will happen?
A. The command will error.
B. The command will complete and update the VLAN database.
C. The command will complete, but before forwarding can happen, the VLAN must be manually created.
D. The command will need to be negated and performed after the VLAN is manually created.
- B. When the command is invoked inside of the interface, it will create the VLAN automatically.
- What is the normal range of VLANs that can be modified on a Cisco switch with default configuration?
A. VLAN 1 to 1002 B. VLAN 1 to 1001 C. VLAN 2 to 1002 D. VLAN 2 to 1001
- D. The normal range of VLANs on a default Cisco switch is VLAN 1 to 1001. However, VLAN 1 cannot be modified.
- Static VLANs are being used on a switch’s interface. Which of the following statements is correct?
A. Nodes use a VLAN policy server.
B. Nodes are assigned VLANs based on their MAC address.
C. Nodes are unaware of the VLAN in which they are configured.
D. All nodes are in the same VLAN.
- C. Static VLANs are VLANs that have been manually configured vs. dynamic VLANs that are configured via a VLAN Membership Policy Server (VMPS). A node will not know which VLAN it is assigned to when it is statically set via the command switchport access vlan 3
- A switch is configured with a single VLAN of 12 for all interfaces. All nodes auto- negotiate at 100 Mb/s full-duplex. What is true if you add an additional VLAN to the switch.
A. The switch will decrease its bandwidth due to overhead. B. The switch will increase its count of collision domains. C. The switch will now require a router.
D. The switch will increase its bandwidth due to broadcast domains.
- D. The addition of another VLAN will increase the effective bandwidth by adding additional broadcast domains. A router is required to route between VLANs. However, it will not be required if you are logically partitioning the switch via VLANs.
- What is a direct benefit of adding VLANs?
A. An increase of broadcast domains while decreasing collision domains B. An increase of broadcast domains while increasing collision domains C. A decrease of broadcast domains while decreasing collision domains
D. A decrease of broadcast domains while increasing collisions domains
- B. When adding VLANs, you immediately increase the number of broadcast domains. At the same time you increase collision domains. If a switch had 12 ports and they all negotiated at 100 Mb/s half-duplex (one collision domain), when a VLAN is added you will automatically create two collision domains while adding an additional broadcast domain
- Which statement describes dynamic VLANs?
A. The access port is switched into the respective VLAN based upon user credentials.
B. The access port is switched into the respective VLAN based upon the computer’s IP address.
C. The access port is switched into the respective VLAN based upon the computer’s MAC address.
D. The access port is switched into the respective VLAN based upon security ACLs.
- C. Dynamic VLANs are deprecated, but you may still see them in operations. A switch configured with dynamic VLANs checks a VLAN Management Policy Server (VMPS) when clients plug in. The VMPS has a list of MAC addresses to their respective VLANs. It is now recommended that dynamic VLAN installations are converted to 802.1x
- You have changed the name of VLAN 3, and you now want to check your change. Which command will you enter to verify the name change?
A. Switch#show vlans
B. Switch#show interface vlan 3 C. Switch#show run
D. Switch#show vlan id 3
- D. To verify a VLAN name change, you would use the command show vlan id 3. This would only show you the one VLAN configured in the database. show vlans is incorrect because the command is not plural; it is singular, show vlan. It will give you a complete listing of all VLANs.
- You have been asked to segment the network for an R&D workgroup. The requirement is to allow the R&D group access to the existing servers, but no other VLANs should be able to access R&D. How can this be achieved with maximum flexibility?
A. Create a new VLAN, configure a routed SVI interface, and apply ACLs to the VLAN.
B. Create a new VLAN, configure a routed SVI interface, and apply ACLs to the R&D ports.
C. Create a new VLAN, and install a new R&D server in the new VLAN.
D. Create a new VLAN, and trunk the existing file server for both the production and R&D network.
- A. Creating the new VLAN will logically segment this work group. Creating a Switched Virtual Interface (SVI) will allow routing on the layer 3 switch. The ACLs should only be applied to VLAN interfaces. Although the other solutions achieve a similar goal, they do not provide flexibility.
- You need to verify that an interface is in the proper VLAN. Which command will display the status of the interface, the VLAN configured, and the operational mode?
A. Switch#show vlan
B. Switch#show running-config C. Switch#show interfaces
D. Switch#show interfaces switchport
- D. The command show interfaces switchport will display a detail of all ports in respect to VLAN operational status. The command will show the operational mode of the interface, such as trunk or access mode.
- You configured VLAN on an interface, but it is not working. After looking at the
VLAN database, you find it has been disabled. Which command will enable the VLAN?
A. Switch#enable vlan 3
B. Switch(config)#enable vlan 3
C. Switch#no shutdown vlan 3
D. Switch(config)#vlan 3 Switch(config-vlan)#no shutdown
- D. The proper way to enable a VLAN to forward traffic is to first enter the VLAN database for ID 3 and then issue the no shutdown command. On some IOS versions, this can also be done via the command no shutdown vlan 3 from global config mode.
- Which of the following is a true statement about static access ports? A. An access port can carry VLANs via tagging.
B. A client computer can request the VLAN to be placed in.
C. A client computer cannot see any VLAN tagging information.
D. A client computer can see the VLAN tagging information.
- C. The client computer connected to an access port cannot see any VLAN tagging information. It is removed before egress of the interface.
- Which of the following is a true statement, if you have changed the MTU on a VLAN to support jumbo frames?
A. If a normal MTU of 1528 is used, the switch will not forward the traffic.
B. Once jumbo frames are configured, nothing more needs to be done. Clients will auto-detect the new MTU and use jumbo frames.
C. Changing the MTU is an easy and effective method for raising speed.
D. For jumbo frames to be effective, all devices on the VLAN, including switches, must support them.
- D. When the MTU is changed on the VLAN, it has little consequence to normal MTU communications. However, if you are going to utilize the new MTU for something like iSCSI, it must be supported end to end or it can actually decrease performance. All switching equipment between the two end devices must support jumbo frames.
- You have configured an access port for a remote office computer. The office has no IT persons on site. You want to stop workers from plugging in a WAP and exposing your company’s internal network. Which feature should you configure?
A. Dynamic VLANs B. Port security
C. ACLs
D. VLANpruning
- B. Since the remote office has no onsite IT personnel, there is a risk of workers plugging in unauthorized equipment such as a WAP. If port security is implemented, the interface can be secured to allow only the MAC address of the computer to pass; all other traffic can be dropped.
- Which is a benefit of implementing routed VLANs?
A. VLANs can span multiple switches.
B. Implementing routed VLANs will decrease the broadcast domains. C. ACLs can be employed to secure VLANs.
D. All of the above
- C. When layer 3 or routed VLANs are implemented, it allows for a more secure network with the use of ACLs applied to the VLAN interface.
- You are running a wireless LAN controller (WLC) for a WLAN. You want to allow for guests to be segmented to the guest VLAN. What will you need to implement on the WLC?
A. Access control lists for one SSID
B. Two SSIDs, one configured to the production VLAN and another configured to the guest VLAN
C. Dynamic VLANs for the SSID
D. Access control lists for two SSIDs
- B. Wireless LAN controllers allow trunks to be used so that multiple VLANs can be used. Once the VLANs are accessible to the WLC, you need to create one SSID tied to the VLAN configured for production and another SSID tied to the VLAN configured for guests
- What is the difference between a default VLAN and a native VLAN?
A. A default VLAN is configured on all access ports of the switch from the factory.
B. A native VLAN is configured on all access ports of the switch from the factory. C. A default VLAN is configured on all trunks for tagged frames.
D. A native VLAN is configured on all trunks for tagged frames.
- A. The default VLAN for all switches is VLAN 1. It is the default configuration for all access ports from the factory.
- Where is the extended VLAN configuration stored?
A. Inthevlan.datfile
B. In the running-config C. In the VLAN database
D. In the startup-config
- D. The extended VLAN database will be stored in the startup-config. Only normal VLANs are stored in the VLAN database (vlan.dat). When configuring extended VLANs, you must have the switch in VTP transparent mode.
- You need to create a new VLAN 5 called office and apply it to interface Fa0/4. Which commands will you need to enter?
A. Switch(config)#vlan 5 Switch(config-vlan)#name office Switch(config-vlan)#exit Switch(config)#interface fast 0/4 Switch(config-if)#switchport access vlan 5
B. Switch(config)#vlan 5
Switch(config-vlan)#name office Switch(config-vlan)#exit Switch(config)#interface fast 0/4 Switch(config-if)#switchport access vlan office
C. Switch(config)#vlan 5 office Switch(config)#interface fast 0/4 Switch(config-if)#switchport access vlan 5
D. Switch(config)#vlan 5 name office Switch(config)#interface fast 0/4 Switch(config-if)#switchport access vlan 5
- A. You should first create the VLAN in the VLAN database and add its name. Then you need to enter the interface and configure the port for the VLAN
- A VLAN was created on another non-Cisco switch. You look at the current VLAN database, but the VLAN is not in the VLAN database. What must be done to correct the issue?
A. Set the correct trunking protocol between the switches. B. Create the VLAN manually.
C. Configure VTP on both switches.
D. Assign the VLAN to an interface on the other switch.
- B. You must manually configure the VLAN on the Cisco switch(s). VTP is a protocol that allows for VLAN autoconfiguration in the VLAN database. However, only Cisco switches support it.
- Which command(s) will rename an existing VLAN 4 from production to office without interruption to the network?
A. Switch(config)#rename vlan 4 office B. Switch(config)#vlan 4
Switch(config-vlan)#name office C. Switch(config)#vlan 4 office
D. Switch(config)#no vlan 4 Switch(config)#vlan 4 Switch(config-vlan)#name office
- B. In global configuration, you first need to enter the entry of the VLAN in the VLAN database. Then you can issue a name command to overwrite the existing entry. Negating the VLAN 4 and re-creating it would also work but would create interruption when it was destroyed.
- You have been tasked to configure an interface with a VLAN ID of 8 and support a VoIP phone on VLAN 6. Which commands would achieve the goal?
A. Switch(config-if)#switchport vlan 8 Switch(config-if)#switchport vlan 6 voip
B. Switch(config-if)#switchport mode access vlan 8 Switch(config-if)#switchport voice vlan 6
C. Switch(config-if)#switchport access vlan 8 Switch(config-if)#switchport voice vlan 6
D. Switch(config-if)#switchport access vlan 8 voice 6
- C. The command used to configure an access port for VLAN 8 is switchport access vlan 8, and the command to configure the VOIP phone is switchport voice vlan 6.
- You attempt to configure a VLAN on a switch of VLAN 2300. When you finish configuring the VLAN and exit the VLAN database, you receive the error “% Failed to create VLANS 2300.” What is wrong?
A. The VLAN database is too large and out of space.
B. The VLAN database cannot be configured for VLAN 2300.
C. The VTP mode must be transparent to configure VLAN 2300.
D. The VLAN must be configured on an interface first.
- C. One of the prerequisites for configuring extended VLANs is that the VTP mode must be transparent
- You attempt to configure a VLAN with a new name. You receive the error “Default VLAN 1 may not have its name changed.” What is wrong?
A. The VLAN is used on interfaces already.
B. The VLAN is protected from any changes.
C. The VLAN is being referenced by its name in interface configuration.
D. You are not in the VLAN database when committing the change.
- B. VLAN 1 is the default VLAN and it is not permitted by the IOS to change the VLAN in any way. This includes name change
- You have configured a VLAN for an MTU of 9128. However, you have noticed a severe performance decrease from the change. What is the problem?
A. One of the connected switches is still configured for a nominal MTU. B. The VLAN configuration must still propagate to the other switches. C. The VTP protocol is not configured correctly.
D. The device does not support jumbo frames.
- A. Although the MTU is configured on the VLAN, all switches and devices connected end to end must be configured to support jumbo frames. If you fail to do this, you can expect to see a performance decrease. An MTU of 9128 is defined as a jumbo frame.
- You have connected a Dell switch to the Cisco switch you are configuring and you cannot get a trunk between the two. What must be changed?
A. The Dell switch must be configured to use ISL.
B. The Cisco switch must be configured to use 802.1Q.
C. Both switches need to have duplicated VLAN configurations.
D. VTP needs to be configured on each of the switches.
- B. Since the Dell switch cannot support the proprietary protocol of ISL, both switches need to be set up to use 802.1Q.
- You need to configure a trunk interface to support the protocol of 802.1Q. Which
command will achieve this?
A. Switch(config-if)#switchport mode trunk 802.1q
B. Switch(config-if)#switchport trunk encapsulation 802.1q C. Switch(config-if)#switchport 802.1q
D. Switch(config-if)#switchport encapsulation trunk 802.1q
- B. The command to specify 802.1Q encapsulation on a trunk interface is switchport trunk encapsulation 802.1q.
- You are trying to configure a trunk port on an interface for 802.1Q encapsulation. However, after entering the proper command, you receive the error % Invalid input detected at ‘^’ marker. What is wrong?
A. 802.1Q is not supported on the switch you are configuring this on. B. The interface will not allow configuration of 802.1Q.
C. The switch only supports the ISL trunking protocol.
D. The switch only supports the 802.1Q trunking protocol.
- D. This error is very common when configuring Cisco switches, since many switches only support 802.1Q and configuration is not necessary. The ISL trunking protocol is not supported on certain platforms, such as the 2900 series switches.
- You need to view all of the trunks on a switch and verify that they have the proper trunking protocols configured. Which command will display the information?
A. Switch#show interfaces brief B. Switch#show interfaces trunk C. Switch#show switchport trunk D. Switch#show switchport brief
- B. The command show interfaces trunk will display all of the configured trunks on the switch
- When a frame is not tagged with 802.1Q VLAN identifying information, what happens when it traverses a trunk port?
A. The frame is dropped to the bit bucket.
B. The frame is forwarded to the default VLAN. C. The frame is forwarded to the native VLAN.
D. The frame is sent to the first VLAN ID configured on the trunk.
- C. When a frame traverses a trunk and does not have VLAN tagging information in the 802.1Q encapsulation format (untagged), it is sent to the native VLAN configured on the trunk.