Cisco CCNA mock exam questions sample test – Question 54

.DRAG DROP
Click and drag the RSTP port state on the left to its matching equivalent STP role, on the right. RSTP port states may be used more than once, and it may not be necessary to use all
RSTP port states.

Select and Place:

54q

Correct Answer:

54a

Explanation:
Rapid Spanning Tree Protocol (RSTP) was developed to reduce the high convergence times required in Spanning Tree Protocol (STP), and introduces the alternate port and backup port. RSTP is an Institute of Electrical and Electronics Engineers (IEEE) standard, 802.1w, and is interoperable with 802.1d (STP). There are fewer transitional states used in RSTP than STP. In RSTP, there are only Forwarding, Learning, and Discarding. The three states are defined as follows:
– Forwarding – the state of all root ports and designated ports. The port is passing traffic.
– Learning – the state of a port that was formerly discarding but due to a change in the topology (link down) it has transitioned to learn its new state. The port could return to discarding or move to forwarding depending on the new topology needs
– Discarding – the state of all non-root and non- designated ports. The port is not passing traffic to prevent potential switching loops.

RSTP can reconfigure the spanning tree in less than a second, compared to the 50 seconds that STP may take. This is achieved through having fewer transition states, the use of
alternate and backup ports, and faster transitions.

Objective:
LAN Switching Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot STP protocols
References:
Cisco > Technology Support > LAN Switching > Spanning Tree Protocol > Technology White Paper > Understanding Rapid Spanning Tree Protocol (802.1w)
Cisco Support > Technology Support > LAN Switching > Spanning Tree Protocol > Troubleshoot and Alerts > Troubleshooting TechNotes > Understanding Rapid Spanning Tree
Protocol (802.1w)
CCNA Routing and Switching Complete Study Guide: Exam 100-105, Exam 200-105, Exam 200-125, 2nd Edition, Chapter 2: LAN Switching Technologies – Configure, verify, and
troubleshoot STP protocols