Spanning Tree Protocol (STP)

l2-redundancy-broadcast-storm

Spanning Tree Protocol (STP)

STP Overview

In Layer 2 domain, redundancy is an important case. To provide redundant links, multiple connections are done between switches. But this redundancy mechanism can cause an undesirable situation that is called “L2 Loop”. To provide L2 redundancy and to avoid L2 loops, Spanning Tree Protocol (STP) has been developed.

During the development period, various versions of STP has been introduced. Different standards has been created beside Cisco specific versions. These STP versions are :

STP (Spanning Tree Protocol) – 802.1D
RSTP (Rapid Spanning Tree Protocol) – 802.1W
PVST+ (Per VLAN Spanning Tree Plus) – Cisco Proprietary
Rapid PVST+ (Rapid Per VLAN Spanning Tree Plus) – Cisco Proprietary
MST (Multiple Spanning Tree) – 802.1s

In this article, mainly we will focus on STP (802.1D).

Redundant Layer 2 Problems

Redundancy is an important term for a network. Layer 2 Redundancy is also important but need more caution. Without a mechanims like STP, Layer 2 Redundancy mechanisms can cause the below problems:

• Layer 2 Loops and Broadcast Storms
• MAC Address Instability
• Duplicate Frame Transmission

Let’s talk about each of these Layer 2 Redundacy problems.

Other STP Articles

Spanning Tree Protocol – STP Overview
Spanning Tree Protocol – STP Operation
Spanning Tree Protocol – RSTP Overview
Spanning Tree Protocol – STP Portfast Configuration on Cisco
Spanning Tree Protocol – RSTP Configuration on Cisco
Spanning Tree Protocol – STP Configuration on Huawei
Spanning Tree Protocol – RSTP Configuration on Huawei

3 Responses to “Spanning Tree Protocol (STP)”


  • Gaurav / Reply

    Dear Sir,
    I have checked your blog. It’s have very important topic.All type engineer again the help with this.
    Sir, I want to some note for Switching. Can you help me on this.
    I want

  • ratan / Reply

    hi sir this is very nice site and good explain.i have always follow this site,please upload mst(multi spanning tree) in depth

Leave a Reply