Do I Know This Already Chapter 6
Which of the following statements describes part of the process of how a switch decides to forward a frame destined for a known unicast MAC address? a. It compares the unicast destination address to the bridging, or MAC address, table. b. It compares the unicast source address to the bridging, or MAC address, table. c. It forwards the frame out all interfaces in the same VLAN except for the incoming interface. d. It compares the destination IP address to the destination MAC address. e. It compares the frame's incoming interface to the source MAC entry in the MAC address table.
A (It compares the unicast destination address to the bridging, or MAC address, table.) . A switch compares the destination address to the MAC address table. If a matching entry is found, the switch knows out which interface to forward the frame. If no matching entry is found, the switch floods the frame.
Which of the following statements best describes what a switch does with a frame destined for an unknown unicast address? a. It forwards out all interfaces in the same VLAN except for the incoming interface. b. It forwards the frame out the one interface identified by the matching entry in the MAC address table. c. It compares the destination IP address to the destination MAC address. d. It compares the frame's incoming interface to the source MAC entry in the MAC address table.
A (It forwards out all interfaces in the same VLAN except for the incoming interface.) . A switch floods broadcast frames, multicast frames (if no multicast optimizations are enabled), and unknown unicast destination frames (frames whose destination MAC address is not in the MAC address table).
Which of the following devices would be in the same broadcast domain as PC1? (Choose three answers.) a. PC2, which is separated from PC1 by an Ethernet hub b. PC3, which is separated from PC1 by a transparent bridge c. PC4, which is separated from PC1 by an Ethernet switch d. PC5, which is separated from PC1 by a router
A (PC2, which is separated from PC1 by an Ethernet hub) , B (PC3, which is separated from PC1 by a transparent bridge) , and C (PC4, which is separated from PC1 by an Ethernet switch) . A broadcast domain contains all devices whose sent broadcast frames should be delivered to all the other devices in the domain. Hubs, repeaters, bridges, and switches do not separate or segment a LAN into multiple broadcast domains, whereas routers do.
Which of the following devices would be in the same collision domain as PC1? a. PC2, which is separated from PC1 by an Ethernet hub b. PC3, which is separated from PC1 by a transparent bridge c. PC4, which is separated from PC1 by an Ethernet switch d. PC5, which is separated from PC1 by a router
A (PC2, which is separated from PC1 by an Ethernet hub) . A collision domain contains all devices whose frames could collide with frames sent by all the other devices in the domain. Bridges, switches, and routers separate or segment a LAN into multiple collision domains, whereas hubs and repeaters do not.
PC1, with MAC address 1111.1111.1111, is connected to Switch SW1's Fa0/1 interface. PC2, with MAC address 2222.2222.2222, is connected to SW1's Fa0/2 interface. PC3, with MAC address 3333.3333.3333, connects to SW1's Fa0/3 interface. The switch begins with no dynamically learned MAC addresses, followed by PC1 sending a frame with a destination address of 2222.2222.2222. If the next frame to reach the switch is a frame sent by PC3, destined for PC2's MAC address of 2222.2222.2222, which of the following are true? (Choose two answers.) a. The switch forwards the frame out interface Fa0/1. b. The switch forwards the frame out interface Fa0/2. c. The switch forwards the frame out interface Fa0/3. d. The switch discards (filters) the frame.
A (The switch forwards the frame out interface Fa0/1.) and B (The switch forwards the frame out interface Fa0/2.) . When the frame sent by PC3 arrives at the switch, the switch has learned a MAC address table entry for only 1111.1111.1111, PC1's MAC address. PC3's frame, addressed to 2222.2222.2222, is flooded, which means it is forwarded out all interfaces except for the interface on which the frame arrived.
Which of the following Ethernet standards support a maximum cable length of longer than 100 meters? (Choose two answers.) a. 100BASE-T b. 1000BASE-LX c. 1000BASE-T d. 100BASE-FX
B (1000BASE-LX) and D (100BASE-FX ) . The IEEE Ethernet standards support 100-meter links when using UTP cabling. Most standards that use fiber-optic cabling, like the standards in the two correct answers, use lengths longer than 100 meters.
Which of the following comparisons does a switch make when deciding whether a new MAC address should be added to its MAC address table? a. It compares the unicast destination address to the bridging, or MAC address, table. b. It compares the unicast source address to the bridging, or MAC address, table. c. It compares the VLAN ID to the bridging, or MAC address, table. d. It compares the destination IP address's ARP cache entry to the bridging, or MAC address, table.
B (It compares the unicast source address to the bridging, or MAC address, table.) . Switches need to learn the location of each MAC address used in the LAN relative to that local switch. When a switch sends a frame, the source MAC identifies the sender. The interface in which the frame arrives identifies the local switch interface closest to that node in the LAN topology.
Which of the following statements describes part of the process of how a LAN switch decides to forward a frame destined for a broadcast MAC address? a. It compares the unicast destination address to the bridging, or MAC address, table. b. It compares the unicast source address to the bridging, or MAC address, table. c. It forwards the frame out all interfaces in the same VLAN except for the incoming interface. d. It compares the destination IP address to the destination MAC address.
C (It forwards the frame out all interfaces in the same VLAN except for the incoming interface.) . A switch floods broadcast frames, multicast frames (if no multicast optimizations are enabled), and unknown unicast destination frames (frames whose destination MAC address is not in the MAC address table).
A Cisco LAN switch connects to three PCs (PC1, PC2, and PC3), each directly using a cable that supports Ethernet UTP speeds up through 1000 Mbps (1 Gbps). PC1 uses a NIC that supports only 10BASE-T, while PC2 has a 10/100 NIC, and PC3 has a 10/100/1000 NIC. Assuming that the PCs and switch use IEEE autonegotiation, which PCs will use half-duplex? a. PC1 b. PC2 c. PC3 d. None of the PCs will use half-duplex.
D (None of the PCs will use half-duplex. ) . Full-duplex can be used on any Ethernet link between a switch and a PC. The IEEE autonegotiation process states that the two endpoints on a link should choose the best speed and the best duplex that both support, with full-duplex being better than half-duplex.
