At which OSI layer does STP operate?

A. Physical

B. Network

C. Transport

D. Data Link








 

Suggested Answer: D

Spanning Tree Protocol (STP) operates at the Data Link layer (Layer 2) of the OSI model.
Switches and bridges running the spanning-tree algorithm communicate by exchanging multicast messages called bridge protocol data units (BPDUs) at regular intervals. BPDUs are used to build and maintain the spanning tree, ensuring a stable loop-free topology.
BPDU exchange facilitates the following:
Election of a root switch (only one per spanning tree)
Election of a designated switch for each switched segment
Removal of loops by placing redundant switch ports in a backup (non-forwarding) state
STP is implemented on bridges and switches in order to prevent loops in the network. STP should be used in situations where redundant links are used.
Objective:
Layer 2 Technologies -
Sub-Objective:
Configure and verify spanning tree
References:
Cisco > Home > Support > Technology Support > LAN Switching > Spanning Tree Protocol > Configure > Configuration Examples and Technotes > Spanning
Tree Protocol > Understanding and Configuring Spanning Tree Protocol (STP) on Catalyst Switches
Cisco > Support > Configuring Spanning Tree Protocol > How STP Works

This question is in 300-115 Implementing Cisco IP Switched Networks (SWITCH) Exam
For getting Cisco Certified Network Professional (CCNP) Routing and Switching Certificate





Disclaimers:
The website is not related to, affiliated with, endorsed or authorized by Cisco.
Trademarks, certification & product names are used for reference only and belong to Cisco.
The website does not contain actual questions and answers from Cisco's Certification Exam.