Spanning Tree Protocol Q/A's

Question 1

Rapid Per-VLAN Spanning Tree Protocol (RPVST+) prevents routing loops for each what in Spanning Tree Protocol?

Answer 1

Individual VLAN instance.

Question 2

Rapid Per-VLAN Spanning Tree blocks what two states for faster convergence?

Answer 2

blocking and listening

Question 3

The root port in Spanning Tree Protocol is directly connected to a?

The root bridge is selected by the highest or lowest path cost?

Answer 3

Root Bridge Switch

Lowest path cost

Question 4

The designated port in Spanning Tree Protocol forward frames to what?

Answer 4

each LAN-Local area Network

Question 5

The alternate port in Spanning Tree Protocol is the next available what, to the root bridge?

Answer 5

backup port

Question 6

The blocking port in Spanning Tree Protocol does what with all frames received on that port?

Answer 6

discards

Question 7

In order what are the five transitioning states of Spanning Tree Protocol?

Answer 7

Disabled
Blocking
Listening
Learning
Forwarding
Broken

Question 8

In order what are the three transitioning states of RSTP-Rapid Spanning Tree Protocol?

Answer 8

Discarding “aka blocking port”
Learning
Forwarding

Question 9

The Bridge Protocol Data Units-BPDU’s contain what type of information frames in Spanning Tree Protocol?

Answer 9

spanning tree topology

Question 10

The two things that determine the root bridge switch are the two lowest what?

Answer 10

Bridge ID

Priority

Question 11

Spanning Tree Protocol takes about how long before port forwarding starts?

Answer 11

15 Seconds for Listening and 15 Seconds for Learning (30 seconds)

Question 12

The default Bridge Priority Value for Spanning Tree Protocol is?

Answer 12

32768

Question 13

When the priority value is tied in Spanning Tree Protocol, what is used instead for the selection process?

Answer 13

lowest MAC address

Question 14

Is Spanning Tree Protocol a routing protocol and does it perform load balancing?

What are the two main purposes of Spanning Tree Protocol?

Answer 14

no

prevent loops + best forwarding path

Question 15

In Spanning Tree Protocol the ports that face away from the Root Bridge are called what type of ports?

Answer 15

Designated Ports

Question 16

Spanning Tree Protocol sends BPDU’s to/from?

Answer 16

all ports

Question 17

The main purpose of Spanning Tree “Root Guard”?

Answer 17

Prevent switch from becoming a root bridge

Question 18

The ports on the root bridge are all what type of ports?

Answer 18

Designated ports

Question 19

What are the two types of BPDU’s?

Answer 19

Configuration BPDU

TCN (Topology Change Notification) BPDU

Question 20

The root path cost is always zero on the root bridge? True/False

Answer 20

True

Question 21

Root port is selected in what order?

Answer 21

lowest path cost
lowest system priority
lowest mac address
lowest port priority

Question 22

What is a P2P port type?

Answer 22

port that connects to another network device (PC or Switch)

Question 23

What is P2P edge port type?

Answer 23

port that specifies port fast is enabled

Question 24

When root guard is enabled and a superior BPDU is received on a configured port what happens?

Answer 24

Port goes into a Err-Disabled state

Question 25

Does Portfast disable TCN Topology Change Notifications for access ports. True/False

Answer 25

True

Question 26

The use of spanning-tree portfast trunk should only be used when?

What should this command not be use with?

Answer 26

With ports that are connecting to a single host, ex server with on NIC.

switches, bridges, etc

Question 27

What is the purpose of using BPDU filter?

Answer 27

block BPDU’s from being transmitted out of a port

Question 28

What is the purpose of STP Loop Guard?

Answer 28

prevent any alternative or root ports from becoming designated ports

Question 29

What role does designated ports have?

Answer 29

forward data downstream to other switches/LANs

Question 30

Why shouldn’t loop guard be enabled on portfast-enabled ports?

Answer 30

conflicts with the root/alternative port logic

Question 31

What is Unidirectional Link Detection?

Answer 31

allows (bidirectional) two way monitoring of fiber-optic cables