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Spanning-tree mode – Accton Technology Edge-corE Fast Ethernet Switch ES3528M-SFP User Manual

Page 515

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Spanning Tree Commands

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an STA-compliant switch, bridge or router) in your network to ensure that only
one route exists between any two stations on the network, and provide backup
links which automatically take over when a primary link goes down.

Example
This example shows how to enable the Spanning Tree Algorithm for the switch:

spanning-tree mode

This command selects the spanning tree mode for this switch. Use the no form to
restore the default.

Note:

MSTP is not supported in the current software.

Syntax

spanning-tree mode {stp | rstp

|

mstp}

no spanning-tree mode

stp - Spanning Tree Protocol (IEEE 802.1D)
rstp - Rapid Spanning Tree Protocol (IEEE 802.1w)
mstp - Multiple Spanning Tree (IEEE 802.1s)

Default Setting

rstp

Command Mode

Global Configuration

Command Usage

• Spanning Tree Protocol

Uses RSTP for the internal state machine, but sends only 802.1D BPDUs.
- This creates one spanning tree instance for the entire network. If multiple

VLANs are implemented on a network, the path between specific VLAN
members may be inadvertently disabled to prevent network loops, thus
isolating group members. When operating multiple VLANs, we recommend
selecting the MSTP option.

• Rapid Spanning Tree Protocol

RSTP supports connections to either STP or RSTP nodes by monitoring
the incoming protocol messages and dynamically adjusting the type of
protocol messages the RSTP node transmits, as described below:
- STP Mode – If the switch receives an 802.1D BPDU after a port’s migration

delay timer expires, the switch assumes it is connected to an 802.1D bridge
and starts using only 802.1D BPDUs.

- RSTP Mode – If RSTP is using 802.1D BPDUs on a port and receives an

RSTP BPDU after the migration delay expires, RSTP restarts the migration
delay timer and begins using RSTP BPDUs on that port.

Console(config)#spanning-tree
Console(config)#