The Ultimate CCNA Rstp Quiz

Reviewed by Editorial Team
The ProProfs editorial team is comprised of experienced subject matter experts. They've collectively created over 10,000 quizzes and lessons, serving over 100 million users. Our team includes in-house content moderators and subject matter experts, as well as a global network of rigorously trained contributors. All adhere to our comprehensive editorial guidelines, ensuring the delivery of high-quality content.
Learn about Our Editorial Process
| By Rap
R
Rap
Community Contributor
Quizzes Created: 12 | Total Attempts: 45,775
| Attempts: 1,136
Quiz Flashcard
SettingsSettings
Please wait...
  • 1/9 Questions

    Which command enables RSTP on a switch?

    • Spanning-tree mode rapid-pvst
    • Spanning-tree uplinkfast
    • Spanning-tree backbonefast
    • Spanning-tree mode mst
Please wait...
The Ultimate CCNA Rstp Quiz - Quiz
About This Quiz

Welcome to a helpful quiz for your ongoing progress towards the Cisco Certified Network Associate, where today we’ll be focusing our attention on the Rapid Spanning Tree Protocol – a network protocol which ensures loop-free topology for Ethernet networks. What do you know about it?

Quiz Preview

  • 2. 
    Refer to the exhibit:Why has this switch not been elected the root bridge for VLAN1? - ProProfs

    Refer to the exhibit:Why has this switch not been elected the root bridge for VLAN1?

    • It has more than one internee that is connected to the root network segment.

    • It is running RSTP while the elected root bridge is running 802.1d spanning tree.

    • It has a higher MAC address than the elected root bridge.

    • It has a higher bridge ID than the elected root bridge.

    Correct Answer
    A. It has a higher bridge ID than the elected root bridge.
    Explanation
    As we can see from the output above, the priority of the root bridge is 20481 while that of the local bridge is 32769.

    Rate this question:

  • 3. 

    Which two of these statements regarding RSTP are correct? (Choose two)

    • RSTP cannot operate with PVST+.

    • RSTP defines new port roles.

    • RSTP defines no new port states.

    • RSTP is a proprietary implementation of IEEE 802.1D STP.

    • RSTP is compatible with the original IEEE 802.1D STP.

    Correct Answer(s)
    A. RSTP defines new port roles.
    A. RSTP is compatible with the original IEEE 802.1D STP.
    Explanation
    RSTP defines new port roles to enhance the functionality and efficiency of spanning tree protocol. These new port roles include alternate port, backup port, and edge port. RSTP also maintains compatibility with the original IEEE 802.1D STP, ensuring that existing STP implementations can seamlessly transition to RSTP without any compatibility issues.

    Rate this question:

  • 4. 
    Refer to the exhibit. At the end of an RSTP election process, which access layer switch port will assume the discarding role? - ProProfs

    Refer to the exhibit. At the end of an RSTP election process, which access layer switch port will assume the discarding role?

    • Switch3, port fa0/1

    • Switch3, port fa0/12

    • Switch4, port fa0/11

    • Switch4, port fa0/2

    • Switch3, port Gi0/1

    Correct Answer
    A. Switch4, port fa0/11
    Explanation
    In this question, we only care about the Access Layer switches (Switch3 & 4). Switch 3 has a lower bridge ID than Switch 4 (because the MAC of Switch3 is smaller than that of Switch4) so both ports of Switch3 will be in forwarding state. The alternative port will surely belong to Switch4.

    Switch4 will need to block one of its ports to avoid a bridging loop between the two switches. But how does Switch4 select its blocked port? Well, the answer is based on the BPDUs it receives from Switch3. A BPDU is superior than another if it has:

    1. A lower Root Bridge ID
    2. A lower path cost to the Root
    3. A lower Sending Bridge ID
    4. A lower Sending Port ID

    These four parameters are examined in order. In this specific case, all the BPDUs sent by Sswitch3 have the same Root Bridge ID, the same path cost to the Root and the same Sending Bridge ID. The only parameter left to select the best one is the Sending Port ID (Port ID = port priority + port index). In this case the port priorities are equal because they use the default value, so Switch4 will compare port index values, which are unique to each port on the switch, and because Fa0/12 is inferior to Fa0/1, Switch4 will select the port connected with Fa0/1 (of Switch3) as its root port and block the other port -> Port fa0/11 of Switch4 will be blocked (discarding role).

    If you are still not sure about this question, please read my RSTP tutorial.

    Rate this question:

  • 5. 
    Refer to the exhibit. Which statement is true? - ProProfs

    Refer to the exhibit. Which statement is true?

    • The Fa0/11 role confirms that SwitchA is the root bridge for VLAN 20.

    • VLAN 20 is running the Per VLAN Spanning Tree Protocol.

    • The MAC address of the root bridge is 0017.596d.1580.

    • SwitchA is not the root bridge, because not all of the interface roles are designated.

    Correct Answer
    A. SwitchA is not the root bridge, because not all of the interface roles are designated.
    Explanation
    Only non-root bridge can have root port. Fa0/11 is the root port so we can confirm this switch is not the root bridge -> A is not correct.

    From the output we learn this switch is running Rapid STP, not PVST -> B is not correct.

    0017.596d.1580 is the MAC address of this switch, not of the root bridge. The MAC address of the root bridge is 0017.596d.2a00 -> C is not correct.

    All of the interface roles of the root bridge are designated. SwitchA has one Root port and 1 Alternative port so it is not the root bridge -> D is correct.

    Rate this question:

  • 6. 

    Which three statements about RSTP are true? (Choose three)

    • RSTP significantly reduces topology reconvening time after a link failure.

    • RSTP expands the STP port roles by adding the alternate and backup roles.

    • RSTP port states are blocking, discarding, learning, or forwarding.

    • RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.

    • RSTP also uses the STP proposal-agreement sequence.

    • RSTP uses the same timer-based process as STP on point-to-point links.

    Correct Answer(s)
    A. RSTP significantly reduces topology reconvening time after a link failure.
    A. RSTP expands the STP port roles by adding the alternate and backup roles.
    A. RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.
    Explanation
    RSTP significantly reduces topology reconvening time after a link failure because it uses a faster convergence mechanism compared to STP. RSTP expands the STP port roles by adding the alternate and backup roles, providing additional redundancy in the network. Additionally, RSTP provides a faster transition to the forwarding state on point-to-point links than STP does, improving the overall network performance.

    Rate this question:

  • 7. 

    Which two states are the port states when RSTP has converged? (choose two)

    • Blocking

    • Learning

    • Disabled

    • Forwarding

    • Listening

    Correct Answer(s)
    A. Blocking
    A. Forwarding
    Explanation
    RSTP only has 3 port states that are discarding, learning and forwarding. When RSTP has converged there are only 2 port states left: discarding and forwarding but the answers don’t mention about discarding state so blocking state (answer A) may be considered the best alternative answer.

    Rate this question:

  • 8. 
    Refer to the exhibit. Each of these four switches has been configured with a hostname, as well as being configured to run RSTP. No other configuration changes have been made. Which three of these show the correct RSTP port roles for the indicated switches and interfaces? (Choose three) - ProProfs

    Refer to the exhibit. Each of these four switches has been configured with a hostname, as well as being configured to run RSTP. No other configuration changes have been made. Which three of these show the correct RSTP port roles for the indicated switches and interfaces? (Choose three)

    • SwitchA, Fa0/2, designated

    • SwitchA, Fa0/1, root

    • SwitchB, Gi0/2, root

    • SwitchB, Gi0/1, designated

    • SwitchC, Fa0/2, root

    • SwitchD, Gi0/2, root

    Correct Answer(s)
    A. SwitchA, Fa0/2, designated
    A. SwitchA, Fa0/1, root
    A. SwitchD, Gi0/2, root
    Explanation
    The question says “no other configuration changes have been made” so we can understand these switches have the same bridge priority. Switch C has lowest MAC address so it will become root bridge and 2 of its ports (Fa0/1 & Fa0/2) will be designated ports -> E is incorrect. Because SwitchC is the root bridge so the 2 ports nearest SwitchC on SwitchA (Fa0/1) and SwitchD (Gi0/2) will be root ports -> B and F are correct. Now we come to the most difficult part of this question: SwitchB must have a root port so which port will it choose? To answer this question we need to know about STP cost and port cost. In general, “cost” is calculated based on bandwidth of the link. The higher the bandwidth on a link, the lower the value of its cost. Below are the cost values you should memorize:SwitchB will choose the interface with lower cost to the root bridge as the root port so we must calculate the cost on interface Gi0/1 & Gi0/2 of SwitchB to the root bridge. This can be calculated from the “cost to the root bridge” of each switch because a switch always advertises its cost to the root bridge in its BPDU. The receiving switch will add its local port cost value to the cost in the BPDU.One more thing to notice is that a root bridge always advertises the cost to the root bridge (itself) with an initial value of 0.Now let’s have a look at the topology again

    Rate this question:

  • 9. 
    Refer to the exhibit. The output that is shown is generated at a switch. Which three of these statements are true? (Choose three) - ProProfs

    Refer to the exhibit. The output that is shown is generated at a switch. Which three of these statements are true? (Choose three)

    • All ports will be in a state of discarding, learning or forwarding.

    • Thirty VLANs have been configured on this switch.

    • The bridge priority is lower than the default value for spanning tree.

    • All interfaces that are shown are on shared media.

    • All designated ports are in a forwarding state.

    • The switch must be the root bridge for all VLANs on this switch.

    Correct Answer(s)
    A. All ports will be in a state of discarding, learning or forwarding.
    A. The bridge priority is lower than the default value for spanning tree.
    A. All designated ports are in a forwarding state.
    Explanation
    From the output, we see that all ports are in Designated role (forwarding state) -> A and E are correct.

    The command “show spanning-tree vlan 30″ only shows us information about VLAN 30. We don’t know how many VLAN exists in this switch -> B is not correct.

    The bridge priority of this switch is 24606 which is lower than the default value bridge priority 32768 -> C is correct.

    All three interfaces on this switch have the connection type “p2p”, which means Point-to-point environment – not a shared media -> D is not correct.

    The only thing we can specify is this switch is the root bridge for VLAN 3o but we can not guarantee it is also the root bridge for other VLANs -> F is not correct.

    Rate this question:

Quiz Review Timeline (Updated): Mar 22, 2023 +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

  • Current Version
  • Mar 22, 2023
    Quiz Edited by
    ProProfs Editorial Team
  • Mar 17, 2015
    Quiz Created by
    Rap
Back to Top Back to top
Advertisement
×

Wait!
Here's an interesting quiz for you.

We have other quizzes matching your interest.