CNIT 315 PROFESSIONAL IT SECURITY PREP
QUESTIONS AND ACCURATE ANSWERS
GRADED A+
●● How are MAC broadcast domains segmented?
Answer: - segmented by a router
●● True/False: Large collision domains are bad
Answer: True
●● What are some problems that VLANs address?
Answer: - mobile users
- geographically separated users
- security between and within network segments
- latency and delays
●● Prior to VLANs, what was the only solution to separate network
segments?
Answer: - layer separation was physical-only
●● What are some of the main uses of VLANs?
Answer: - further segmentation of the LAN
,- increases scalability
- provides flexibility in LAN operation
- increases granularity of control
●● What is the main purpose of a VLAN?
Answer: - to logically segment the network
- segment the media access domain
●● What are the different types of VLANs?
Answer: - tag-based
- port-based
- MAC-based
- Layer 3 VLANs
●● What is the most common type of VLAN in use today?
Answer: - tag-based (802.1Q)
●● What is the InterSwitch Link (ISL) tag-based VLAN architecture?
Answer: - Cisco proprietary
- encapsulates the entire Ethernet Frame
- 1000 possible unique VLANs
,●● What is the IEEE 802.1Q tag-based VLAN architecture?
Answer: - extends 802.1D
- inserts a tag into the Ethernet frame
- 4096 possible unique VLANs
●● How many bytes does an ISL header consist of?
Answer: 26 bytes
●● How many bytes does an ISL CRC consist of?
Answer: 4 bytes
●● How many bits does an ISL VLAN ID consist of?
Answer: 15 bits
●● How do 802.1Q tag-based VLANs work?
Answer: - incorporate a 4-byte "shim" into the Ethernet frame
●● How many bits makeup an 802.1Q VLAN ID?
Answer: 12 bits
●● What does an 802.1Q VLAN ID of 0 indicate?
, Answer: - indicates frame isn't a member of any VLAN (called priority
tagging as only the priority field is used)
●● True/False: All traffic within a VLAN needs to be tagged
Answer: False
●● What will be connected to edge interfaces in a VLAN architecture?
Answer: - hosts
●● What will be connected to trunked interfaces in a VLAN
architecture?
Answer: - other switches
●● True/False: Traffic must be tagged on a trunked interface
Answer: True
●● What is VLAN trunking?
Answer: - multiplexes multiple VLANs over a single physical
connection (or single logical connection; ie. aggregate links)
- each VLAN can maintain its own STP topology, iP range, and network
requirements
●● What is the VLAN Trunking Protocol (VTP)?
QUESTIONS AND ACCURATE ANSWERS
GRADED A+
●● How are MAC broadcast domains segmented?
Answer: - segmented by a router
●● True/False: Large collision domains are bad
Answer: True
●● What are some problems that VLANs address?
Answer: - mobile users
- geographically separated users
- security between and within network segments
- latency and delays
●● Prior to VLANs, what was the only solution to separate network
segments?
Answer: - layer separation was physical-only
●● What are some of the main uses of VLANs?
Answer: - further segmentation of the LAN
,- increases scalability
- provides flexibility in LAN operation
- increases granularity of control
●● What is the main purpose of a VLAN?
Answer: - to logically segment the network
- segment the media access domain
●● What are the different types of VLANs?
Answer: - tag-based
- port-based
- MAC-based
- Layer 3 VLANs
●● What is the most common type of VLAN in use today?
Answer: - tag-based (802.1Q)
●● What is the InterSwitch Link (ISL) tag-based VLAN architecture?
Answer: - Cisco proprietary
- encapsulates the entire Ethernet Frame
- 1000 possible unique VLANs
,●● What is the IEEE 802.1Q tag-based VLAN architecture?
Answer: - extends 802.1D
- inserts a tag into the Ethernet frame
- 4096 possible unique VLANs
●● How many bytes does an ISL header consist of?
Answer: 26 bytes
●● How many bytes does an ISL CRC consist of?
Answer: 4 bytes
●● How many bits does an ISL VLAN ID consist of?
Answer: 15 bits
●● How do 802.1Q tag-based VLANs work?
Answer: - incorporate a 4-byte "shim" into the Ethernet frame
●● How many bits makeup an 802.1Q VLAN ID?
Answer: 12 bits
●● What does an 802.1Q VLAN ID of 0 indicate?
, Answer: - indicates frame isn't a member of any VLAN (called priority
tagging as only the priority field is used)
●● True/False: All traffic within a VLAN needs to be tagged
Answer: False
●● What will be connected to edge interfaces in a VLAN architecture?
Answer: - hosts
●● What will be connected to trunked interfaces in a VLAN
architecture?
Answer: - other switches
●● True/False: Traffic must be tagged on a trunked interface
Answer: True
●● What is VLAN trunking?
Answer: - multiplexes multiple VLANs over a single physical
connection (or single logical connection; ie. aggregate links)
- each VLAN can maintain its own STP topology, iP range, and network
requirements
●● What is the VLAN Trunking Protocol (VTP)?
