SMC Networks 16 10BASE-T Configuring Global Settings, Global settings apply to the entire switch

Spanning Tree Algorithm Configuration 3

Configuring Global Settings

Global settings apply to the entire switch.

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.

•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 (i.e., STP 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.

Command Attributes

Basic Configuration of Global Settings

•Spanning Tree State – Enables/disables STA on this switch. (Default: Enabled)

•Spanning Tree Type – Specifies the type of spanning tree used on this switch:

-STP: Spanning Tree Protocol (IEEE 802.1D); i.e., when this option is selected, the switch will use RSTP set to STP forced compatibility mode).

-RSTP: Rapid Spanning Tree (IEEE 802.1w); RSTP is the default.

•Priority – Bridge priority is used in selecting the root device, root port, and designated port. The device with the highest priority becomes the STA root device. However, if all devices have the same priority, the device with the lowest MAC address will then become the root device. (Note that lower numeric values indicate higher priority.)

-Default: 32768

-Range: 0-61440, in steps of 4096

-Options: 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, 61440

Root Device Configuration

•Hello Time – Interval (in seconds) at which the root device transmits a configuration message.

-Default: 2

-Minimum: 1

-Maximum: The lower of 10 or [(Max. Message Age / 2) -1]

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