802.1s Multiple Spanning Tree Protocol (MSTP)

The switches covered in this guide use the IEEE 802.1s Multiple Spanning Tree Protocol (MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network.) standard.

The 802.1D and 802.1w spanning tree protocols operate without regard to a network's VLAN Virtual Local Area Network. Separate logical broadcast domain created within a physical network. configuration, and maintain one common spanning tree throughout a bridged network. Thus, these protocols map one loop-free, logical topology on a given physical topology. The 802.1s Multiple Spanning Tree protocol (MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network.) uses VLANs to create multiple spanning trees in a network, which significantly improves network resource utilization while maintaining a loop-free environment.

While the per-VLAN Virtual Local Area Network. Separate logical broadcast domain created within a physical network. spanning tree approach adopted by some vendors overcomes the network utilization problems inherent in using STP Spanning Tree Protocol. A network protocol that builds a loop-free logical topology for ethernet networks. or RSTP, using a per-VLAN Virtual Local Area Network. Separate logical broadcast domain created within a physical network. technology with multiple VLANs can overload the switch's CPU. MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network. on the switches covered in this guide complies with the IEEE 802.1s standard, and extends STP Spanning Tree Protocol. A network protocol that builds a loop-free logical topology for ethernet networks. and RSTP functionality to map multiple independent spanning tree instances onto a physical topology. With MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network., each spanning tree instance can include one or more VLANs and applies a separate, per-instance forwarding topology. Thus, where a port belongs to multiple VLANs, it may be dynamically blocked in one spanning tree instance, but forwarding in another instance. This achieves load-balancing across the network while keeping the switch's CPU load at a moderate level (by aggregating multiple VLANs in a single spanning tree instance). MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network. provides fault tolerance through rapid, automatic reconfiguration if there is a failure in a network's physical topology.

With MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network.-capable switches, you can create a number of MST regions containing multiple spanning tree instances. This requires the configuration of a number of MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network.-capable switches. However, it is not necessary to do this. You can enable MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network. on an MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network.-capable switch and a spanning tree instance is created automatically. This instance always exists by default when spanning tree is enabled, and is the spanning tree instance that communicates with STP Spanning Tree Protocol. A network protocol that builds a loop-free logical topology for ethernet networks. and RSTP environments. The MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network. configuration commands operate exactly like RSTP commands and MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network. is backward-compatible with the RSTP-enabled and STP Spanning Tree Protocol. A network protocol that builds a loop-free logical topology for ethernet networks.-enabled switches in your network.

In a mesh environment, the default MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network. timer settings (Hello Time and Forward Delay) are usually adequate for MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network. operation. Because a packet crossing a mesh may traverse several links within the mesh, using smaller-than-default settings for the MSTP Multiple Spanning Tree Protocol. A protocol that creates multiple spanning trees (instances) for each Virtual LAN on a single physical network. Hello Time and Forward Delay timers can cause unnecessary topology changes and end-node connectivity problems.