SWITCHING CONCEPTS
What criteria is used by a Cisco LAN switch to decide how to forward Ethernet frames? - Destination IP address - Destination MAC address - Egress port - Path cost
- Destination MAC address
3. What is the significant difference between a hub and a Layer 2 LAN switch? - A hub divides collision domains, and a switch divides broadcast domains. - Each port of a hub is a collision domain, and each port of a switch is a broadcast domain. - A switch creates many smaller collision domains, and a hub increases the size of a single collision domain. - A hub forwards frames, and a switch forwards only packets.
- A switch creates many smaller collision domains, and a hub increases the size of a single collision domain.
1. Which statement is true about broadcast and collision domains? - The size of the collision domain can be reduced by adding hubs to a network. - Adding a switch to a network will increase the size of the broadcast domain. - Adding a router to a network will increase the size of the collision domain. - The more interfaces a router has the larger the resulting broadcast domain.
- Adding a switch to a network will increase the size of the broadcast domain.
Which switching method forwards the frame immediately after examining the destination MAC address? - Broadcast - Cut-though - Large frame buffer - Store-and-forward
- Cut-though
4. What will a Cisco LAN switch do if it receives an incoming frame and the destination MAC address is not listed in the MAC address table? - Send the frame to the default gateway address. - Use ARP to resolve the port that is related to the frame. - Drop the frame. - Forward the frame out all ports except the port where the frame is received.
- Forward the frame out all ports except the port where the frame is received.
9. Which two statements are true about half-duplex and full-duplex communications? (Choose two.) - Half duplex has only one channel. - Full duplex increases the effective bandwidth. - Full duplex allows both ends to transmit and receive simultaneously. - Full duplex offers 100 percent potential use of the bandwidth. - All modern NICS support both half-duplex and full-duplex communication.
- Full duplex increases the effective bandwidth. - Full duplex allows both ends to transmit and receive simultaneously.
Which statement about half-duplex and full-duplex communication is true? - Gigabit Ethernet and 10 Gb/s NICs can operate in full-duplex or half-duplex. - Full-duplex communication is bidirectional. - Half-duplex communication allows both ends to transmit and receive simultaneously. - Half-duplex communication is unidirectional, or one direction at a time.
- Full-duplex communication is bidirectional.
A switch has received a frame on an ingress port. What will the switch do if the destination MAC address is a broadcast address? - It will drop the frame. - It will forward the frame out all ports. - It will forward the frame out all ports except the incoming port. - It will forward the frame out of the specified port in the MAC address table.
- It will forward the frame out all ports except the incoming port.
A switch has received a frame on an ingress port. What will the switch do if the unicast destination MAC address is not in the MAC address table? - It will drop the frame. - It will forward the frame out all ports. - It will forward the frame out all ports except the incoming port. - It will forward the frame out of the specified port in the MAC address table.
- It will forward the frame out all ports except the incoming port.
A switch has received a frame on an ingress port. What will the switch do if the unicast destination MAC address is in the MAC address table? - It will drop the frame. - It will forward the frame out all ports. - It will forward the frame out all ports except the incoming port. - It will forward the frame out of the specified port in the MAC address table.
- It will forward the frame out of the specified port in the MAC address table.
13. What is the purpose of frame buffers on a switch? - They execute checksum values before transmission. - They provide temporary storage of the frame checksum. - They hold traffic, thus alleviating network congestion. - They provide a basic security scan on received frames.
- They hold traffic, thus alleviating network congestion.
What are two reasons a network administrator would segment a network with a Layer 2 switch? (Choose two.) - To create fewer collision domains - To create more broadcast domains - To eliminate virtual circuits - To enhance user bandwidth - To isolate ARP request messages from the rest of the network - To isolate traffic between segments
- To enhance user bandwidth - To isolate traffic between segments
2. What is one function of a Layer 2 switch? - forwards data based on logical addressing - determines which interface is used to forward a frame based on the destination MAC address - duplicates the electrical signal of each frame to every port - learns the port assigned to a host by examining the destination MAC address
- determines which interface is used to forward a frame based on the destination MAC address
5. Which switch characteristic helps alleviate network congestion when a 10 Gbps port is forwarding data to a 1 Gbps port? - high port density - fast port speed - fast internal switching - frame buffering
- frame buffering
12. Which network device can serve as a boundary to divide a Layer 2 broadcast domain? - router - Ethernet hub - access point - Ethernet bridge
- router
10. Which type of address does a switch use to build the MAC address table? - source IP address - source MAC address - destination MAC address - destination IP address
- source MAC address
6. Which switching method makes use of the FCS value? - broadcast - large frame buffer - store-and-forward - cut-through
- store-and-forward
11. Which option correctly describes a switching method? - cut-through: makes a forwarding decision after receiving the entire frame - cut-through: provides the flexibility to support any mix of Ethernet speeds - store-and-forward: forwards the frame immediately after examining its destination MAC address - store-and-forward: ensures that the frame is free of physical and data-link errors
- store-and-forward: ensures that the frame is free of physical and data-link errors
14. Which network device can be used to eliminate collisions on an Ethernet network? - hub - firewall - switch - router
- switch
7. What does the term "port density" represent for an Ethernet switch? - the memory space that is allocated to each switch port - the number of available ports - the speed of each port - the numbers of hosts that are connected to each switch port
- the number of available ports
8. Which information does a switch use to keep the MAC address table information current? - the source MAC address and the incoming port - the source and destination MAC addresses and the incoming port - the source and destination MAC addresses and the outgoing port - the destination MAC address and the incoming port - the source MAC address and the outgoing port - the destination MAC address and the outgoing port
- the source MAC address and the incoming port