CCNA DC FAQ: Spanning Tree Protocol Concepts
Q1. Which of the following IEEE 802.1D port states are stable states used when STP has completed convergence? (Choose three answers.)
Q2. Which of the following are transitory IEEE 802.1D port states used only during the process of STP convergence? (Choose two answers.)
Q3. Which of the following bridge IDs win election as root, assuming that the switches with these bridge IDs are in the same network?
Q4. Which of the following facts determines how often a nonroot switch sends an 802.1D STP hello BPDU message?
a. The hello timer as configured on that switch.
b. The hello timer as configured on the root switch.
c. It is always every 2 seconds.
d. The switch reacts to BPDUs received from the root switch by sending another BPDU 2 seconds after receiving the root BPDU.
Q5. What STP feature causes an interface to be placed in the forwarding state as soon as the interface is physically active?
c. Root Guard
Q6. Switch S1 sits in a LAN that uses RSTP. SW1’s E1/1 port is its root port, with E1/2 as the only other port connected to other switches. SW1 knows that it will use E1/2 as its root port if E1/1 fails. If SW1’s E1/1 interface fails, which of the following is true?
a. SW1 waits 10 times the hello timer (default 10 х 2 = 20 seconds) before reacting.
b. SW1 waits three times the hello timer (default 3 х 2 = 6 seconds) before reacting.
c. SW1 does not wait but makes E1/2 the root port and puts it in a learning state.
d. SW1 does not wait but makes E1/2 the root port and puts it in a forwarding state.
Q7. Switch SW1 sits in a LAN that uses RSTP. SW1 has 24 RSTP edge ports and is also receiving hello BPDUs on two point-to-point ports, E1/1 and E1/2. SW1 chooses E1/1 as its root port. Which of the following about the RSTP port role of E1/2 is true?
a. Backup role
b. Blocking role
c. Discarding role
d. Alternate role