MSTP - Multiple Spanning Tree Protocol

What is MSTP?

MSTP stands for Multiple Spanning Tree Protocol. It is an evolution of the Spanning Tree Protocol (STP) and Rapid STP (RSTP) defined in IEEE 802.1s, allowing multiple spanning trees over a single physical network topology.

Why is MSTP useful?

  • It allows better load balancing by enabling multiple VLANs to use different spanning trees.

  • Improves network redundancy and fault tolerance.

  • Reduces convergence time compared to traditional STP.

  • Helps in preventing loops in Layer 2 networks.

How it works?

  • MSTP groups VLANs into Multiple Spanning Tree Instances (MSTIs).

  • Each instance runs its own STP algorithm over the network.

  • A special region called an MST Region defines which VLANs are mapped to which MSTI.

  • Network switches exchange Bridge Protocol Data Units (BPDUs) to elect root bridges and build loop-free topologies per instance.

Where is MSTP used?

  • Large Layer 2 enterprise networks.

  • Data centers where VLAN segmentation and redundancy are crucial.

  • Managed switches and enterprise-grade networking equipment.

Which OSI layer does this protocol belong to?

  • MSTP operates at Layer 2 (Data Link Layer) of the OSI model.

IS MSTP windows specific?

  • No, MSTP is not Windows-specific.

  • It is a network protocol implemented in network switches and routers, not operating systems.

IS MSTP Linux Specific?

  • No, MSTP is not Linux-specific.

  • However, some Linux-based systems or routers may implement MSTP via networking tools or bridge configurations.

Which Transport Protocol is used by MSTP?

  • MSTP does not use transport protocols like TCP or UDP.

  • It uses Bridge Protocol Data Units (BPDUs) directly at Layer 2 over Ethernet frames.

Which Port is used by MSTP?

  • MSTP does not use any port numbers.

  • It uses a special Ethernet multicast address to send BPDUs: 01:80:C2:00:00:00.

Is MSTP using Client server model?

  • No, MSTP does not follow a client-server model.

  • It is a peer-to-peer protocol where switches coordinate to manage network topology.

Topics in this section,

  • In this section, you are going to learn

  • Terminology

  • Version Info

  • rfc details

  • setup

  • setup

  • packet details

  • usecases

  • features

  • Reference links