CCNA FAQ: Enhanced Switched Technologies
Q1. You receive the following output from a switch:
Which are true regarding this switch? (Choose two.)
A. The switch is a root bridge.
B. The switch is a non-root bridge.
C. The root bridge is four switches away.
D. The switch is running 802.1w.
E. The switch is running STP PVST+.
Q2. If you want to effectively disable STP on a port connected to a server, which command would you use?
A. disable spanning-tree
B. spanning-tree off
C. spanning-tree security
D. spanning-tree portfast
Q3. Which of the following would you use to find the VLANs for which your switch is the root bridge? (Choose two.)
A. show spanning-tree
B. show root all
C. show spanning-tree port root VLAN
D. show spanning-tree summary
Q4. You want to run the new 802.1w on your switches. Which of the following would enable this protocol?
A. Switch(config)#spanning-tree mode rapid-pvst
B. Switch#spanning-tree mode rapid-pvst
C. Switch(config)#spanning-tree mode 802.1w
D. Switch#spanning-tree mode 802.1w
Q5. Which of the following is a layer 2 protocol used to maintain a loop-free network?
Q6. Which statement describes a spanning-tree network that has converged?
A. All switch and bridge ports are in the forwarding state.
B. All switch and bridge ports are assigned as either root or designated ports.
C. All switch and bridge ports are in either the forwarding or blocking state.
D. All switch and bridge ports are either blocking or looping.
Q7. Which of the following modes enable LACP EtherChannel? (Choose two.)
Q8. Which of the following are true regarding RSTP? (Choose three.)
A. RSTP speeds the recalculation of the spanning tree when the layer 2 network topology changes.
B. RSTP is an IEEE standard that redefines STP port roles, states, and BPDUs.
C. RSTP is extremely proactive and very quick, and therefore it absolutely needs the 802.1 delay timers.
D. RSTP (802.1w) supersedes 802.1d while remaining proprietary.
E. All of the 802.1d terminology and most parameters have been changed.
F. 802.1w is capable of reverting to 802.1d to interoperate with traditional switches on a per-port basis.
Q9. What does BPDU Guard perform?
A. Makes sure the port is receiving BPDUs from the correct upstream switch.
B. Makes sure the port is not receiving BPDUs from the upstream switch, only the root.
C. If a BPDU is received on a BPDU Guard port, PortFast is used to shut down the port.
D. Shuts down a port if a BPDU is seen on that port.
Q10. How many bits is the sys-id-ext field in a BPDU?
Q11. There are four connections between two switches running RSTP PVST+ and you want to figure out how to achieve higher bandwidth without sacrificing the resiliency that RSTP provides. What can you configure between these two switches to achieve higher bandwidth than the default configuration is already providing?
A. Set PortFast and BPDU Guard, which provides faster convergence.
B. Configure unequal cost load balancing with RSTP PVST+.
C. Place all four links into the same EtherChannel bundle.
D. Configure PPP and use multilink.
Q12. In which circumstance are multiple copies of the same unicast frame likely to be transmitted in a switched LAN?
A. During high-traffic periods
B. After broken links are reestablished
C. When upper-layer protocols require high reliability
D. In an improperly implemented redundant topology
Q13. You want to configure LACP. Which do you need to make sure are configured exactly the same on all switch interfaces you are using? (Choose three.)
A. Virtual MAC address
B. Port speeds
D. PortFast enabled
E. VLAN information
Q14. Which of the following modes enable PAgP EtherChannel? (Choose two.)
Q15. For this question, refer to the following illustration. SB’s RP to the root bridge has failed.
What is the new cost for SB to make a single path to the root bridge?
Q16. Which of the following would put switch interfaces into EtherChannel port number 1, using LACP? (Choose two.)
A. Switch(config)#interface port-channel 1
B. Switch(config)#channel-group 1 mode active
C. Switch#interface port-channel 1
D. Switch(config-if)#channel-group 1 mode active
Q17. Which two commands would guarantee your switch to be the root bridge for VLAN 30? (Choose two.)
A. spanning-tree vlan 30 priority 0
B. spanning-tree vlan 30 priority 16384
C. spanning-tree vlan 30 root guarantee
D. spanning-tree vlan 30 root primary
Q18. Why does Cisco use its proprietary extension of PVST+ with STP and RSTP?
A. Root bridge placement enables faster convergence as well as optimal path determination.
B. Non-root bridge placement clearly enables faster convergence as well as optimal path determination.
C. PVST+ allows for faster discarding of non-IP frames.
D. PVST+ is actually an IEEE standard called 802.1w.
Q19. Which are states in 802.1d? (Choose all that apply.)
Q20. Which of the following are roles in STP? (Choose all that apply.)
Answer: A, C, D, E, F. The roles a switch port can play in STP are root, non-root, designated, non-designated, forwarding, and blocking. Discarding is used in RSTP, and disabled could be a role, but it’s not listed as a possible answer.