Fundamentals of Networking Chapter 9

What default STP timer length is used for both the listening and learning states? 15 seconds 5 seconds 20 seconds 2 seconds

15 seconds

Refer to the exhibit. Based on the STP port costs shown, which of S3's interfaces will become the root port? 2 1 3 None

2

What is the default IEEE STP port cost for a 10 Gbps Ethernet interface? 2 1 4 10

2

Refer to the exhibit. Based on the STP port costs shown, which of S4's interfaces will become the root port? 3 2 1 None

3

Which of the following bridge IDs wins election as root, assuming that the switches with these bridge IDs are in the same network? 4097:0200.1111.1111 32769:0200.1111.1111 32769:0200.2222.2222 4097:0200.2222.2222 40961:0200.1111.1111

4097:0200.1111.1111

The ________ feature enables a switch to transition a switchport from blocking to forwarding state quickly by bypassing the listening and learning states. PortFast BPDU Guard FastPass host mode

PortFast

What STP feature causes an interface to be placed in the forwarding state as soon as the interface is physically active? PortFast STP EtherChannel Root Guard

PortFast

Which of the following are functions provided by the Spanning Tree Protocol (STP)? Each correct answer represents a complete solution. Choose all that apply. Prevents broadcast storms Prevents MAC table instability Prevents multiple copies of a single frame from being forwarded Uses TTL to control loops in the network Places a Layer 3 port into blocking state if it is a parallel (redundant) path that would cause a loop

Prevents broadcast storms Prevents MAC table instability Prevents multiple copies of a single frame from being forwarded

What is one way in which STP protects a redundant Ethernet network? Protects against frames looping the Layer 2 domains Reduces collision domain size Identifies and deletes invalid MAC to IP address mapping Makes sure DTP VLANs do not have frame collisions

Protects against frames looping the Layer 2 domains

What is the name of the field in the STP hello BPDU that contains the bridge ID of the switch that the sender of the BPDU believes is the root switch? Root bridge ID Designated bridge ID STP primary ID STP core ID

Root bridge ID

In the exhibit, in VLAN 1, all switches have default STP settings, and all trunks are up and running at 100 Mbps. Which statements are true regarding the behavior of STP in this network, for VLAN 1, after the STP topology has stabilized? Each correct answer represents a complete solution. Choose all that apply. SW1 will create Hello messages regularly based on its Hello timer. SW3's Fa0/1 interface will be in a forwarding state. SW4 will forward a Hello out its Fa0/1 with cost 19. SW2 will create Hello messages regularly based on its Hello timer. SW4's Fa0/1 will become a designated port.

SW1 will create Hello messages regularly based on its Hello timer. SW3's Fa0/1 interface will be in a forwarding state.

Which of the following facts determines how often a nonroot bridge or switch sends an STP Hello BPDU message? The Hello timer as configured on the root switch. The Hello timer as configured on that switch. It is always every 2 seconds. The switch reacts to BPDUs received from the root switch by sending another BPDU 2 seconds after receiving the root BPDU.

The Hello timer as configured on the root switch.

Which of the following are transitory port states used only during the process of STP convergence? Each correct answer represents a complete solution. Choose all that apply. Listening Learning Blocking Forwarding Discarding

Listening Learning

RSTP serves as an improved protocol in comparison to the older STP. Which of the following answers lists a feature of RSTP that does not exist in STP? The criteria used by switches to determine a port to act in the backup port role The criteria used by a nonroot switch to choose its own root port The criteria used by switches to elect a root switch The criteria used by switches to determine the designated port on a segment

The criteria used by switches to determine a port to act in the backup port role

How is a root bridge/switch determined? All the switches send out hello BPDUs, and the switch with the lowest bridge ID becomes the root. All the switches in the internetwork send out hello BPDUs, and the switch that has the aggregate least number of hops to all the other switches becomes the root. All the switches send out hello BPDUs, and the switch with the highest bridge ID becomes the root. The switches send out hello BPDUs, and the switch with the most direct connected switches becomes the root. The core network switch becomes the root.

All the switches send out hello BPDUs, and the switch with the lowest bridge ID becomes the root.

RSTP adds features beyond STP that enable ports to be used for a role if another port on the same switch fails. Which of the following statements correctly describe a port role that is waiting to take over for another port role? Each correct answer represents a complete solution. Choose all that apply. An alternate port waits to become a root port. A backup port waits to become a designated port. A backup port waits to become a root port. An alternate port waits to become a designated port.

An alternate port waits to become a root port. A backup port waits to become a designated port.

An STP topology with three switches has one link between each pair of switches. Which answer best describes the primary decision point as to which non-root switch has a designated port on the link between switches, and which does not? The switch with the lowest root cost would become designated, and the other switch would block. The device with the lowest BID would always become designated, and the other switch would block. The device with the highest BID would become designated, and the other switch would block. The switch with the highest root cost would become designated, and the other switch would block. The switch with the lowest priority setting would become designated, and the other switch would block.

The switch with the lowest root cost would become designated, and the other switch would block.

In what STP state does a port drop all received user traffic and not transmit user traffic but still listen for updated BPDUs? Blocking Dropping Listening Learning

Blocking Dropping

Which of the following port states are stable states used when STP has completed convergence? Each correct answer represents a complete solution. Choose all that apply. Blocking Forwarding Listening Learning Discarding

Blocking Forwarding

What is the name of the new RSTP port state that replaces the STP disabled and blocking states? Discarding Null Monitoring Dropping

Discarding

________ combines multiple parallel segments of equal speed between the same pair of switches. EtherChannel LACP Load balancing STP

EtherChannel

Switch forwarding logic dictates that a switch flood broadcasts out all switchports that are in the same ________, except the switchport in which the frame arrived. VLAN area management domain process

VLAN

The STP root switch is the switch with the lowest numeric value for the ________. bridge ID cost primary ID router ID

bridge ID

A switch's ________ port is its interface through which it has the least STP cost to reach the root switch. root designated forwarding learning

root

The only switch on a LAN that has all designated interfaces is the ________ switch. root main primary forwarding

root

Which of the following RSTP port states have the same name and purpose as a port state in traditional STP? Each correct answer represents a complete solution. Choose all that apply. Forwarding Learning Blocking Listening Discarding

Forwarding Learning

Assuming all default STP settings, which of SW3's ports will become its root port, and what will its root cost be? Gi0/1, 8 Fa0/2, 19 Gi0/1, 4 Fa0/2, 8

Gi0/1, 8

The exhibit shows a diagram of a small switched network. All switches use layer 2 switching and no layer 3 switching. The diagram identifies the root switch (switch SW1), and all root ports (RP) and designated ports (DP) for VLAN 10. All switches have the spanning-tree mode rapid-pvst command configured. The answers list ports that are neither root port nor designated port. Choose the answers that list an RSTP port role that is meaningful for that port in this topology. Each correct answer represents a complete solution. Choose all that apply. SW4's F0/2 could be an RSTP backup port. SW4's G0/1 could be an RSTP alternate port. SW3's F0/4 could be an RSTP alternate port. SW3's F0/4 could be an RSTP backup port. SW2's G0/2 could be an RSTP backup port.

SW4's F0/2 could be an RSTP backup port. SW4's G0/1 could be an RSTP alternate port. SW3's F0/4 could be an RSTP alternate port.

Which is the true statement about STP PortFast mode? The port bypasses the normal STP startup process and enters forwarding mode immediately. Special BPDUs are generated to notify the other switches that the port is an access port and any switches connected to it should cause the port to be disabled. It should be used on all switch uplink ports to speed convergence in case of a network failure. It starts the generation of STP TCN BPDU generation in port up/down conditions.

The port bypasses the normal STP startup process and enters forwarding mode immediately.

The switch that has the lowest STP cost will become the ________ switch for a specific segment. designated root primary forwarding

designated