Spanning-Tree Operation

Configuring Rapid Reconfiguration Spanning Tree (RSTP)

 

Reconfiguring Per-Port Spanning Tree Values. You can configure one

 

or more of the following parameters, which affect the spanning tree operation

 

of the specified ports only:

Table 5-2.

Per-Port RSTP Parameters

 

 

 

Parameter

Default

Description

 

 

 

edge-port

Yes

Identifies ports that are connected to end nodes. During spanning tree

 

 

establishment, these ports transition immediately to the Forwarding state.

 

 

In this way, the ports operate very similarly to ports that are configured in “fast

 

 

mode” under the STP implementation in previous ProCurve switch software.

 

 

Disable this feature on all switch ports that are connected to another switch, or

 

 

bridge, or hub. Use the “no” option on the spanning tree command to disable

 

 

edge-port. This option is available only with RSTP or MSTP operation. (Note that

 

 

when MSTP is enabled, the edge-portdefault setting is disabled.)

 

 

 

mcheck

Yes

Ports with mcheck set to true are forced to send out RSTP BPDUs for 3 seconds.

 

 

This allows for switches that are running RSTP to establish their connection

 

 

quickly and for switches running 802.1D STP to be identified.

 

 

If the whole-switch parameter Force-Version is set to “stp-compatible”, the

 

 

mcheck setting is ignored and STP BPDUs are sent out all ports.

 

 

Disable this feature on all ports that are known to be connected to devices that

 

 

are running 802.1D STP. Use the “no” option on the spanning tree command to

 

 

disable mcheck. This option is available only with RSTP or MSTP operation.

 

 

 

path-cost

10 Mbps – 2 000 000

Assigns an individual port cost that the switch uses to determine which ports

 

100 Mbps – 200 000

are the forwarding ports. The range is 1 to 200,000,000 or auto.

 

1 Gbps – 20 000

By default, this parameter is automatically determined by the port type, as shown

 

 

by the different default values. If you have previously configured a specific value

 

 

for this parameter, you can issue the command with the auto option to restore

 

 

the automatic setting feature.

 

 

Please see the Note on Path Cost on page 5-19 for information on compatibility

 

 

with devices running 802.1D STP for the path cost values.

 

 

 

point-to­

force-true

This parameter is used to tell the port if it is connected to a point-to-point link,

point-mac

 

such as to another switch or bridge or to an end node (force-true).

 

 

This parameter should be set to force-falsefor all ports that are connected to a

 

 

hub, which is a shared LAN segment.

 

 

You can also set this parameter to auto and the switch will automatically set the

 

 

force-false value on all ports that it detects are not running at full duplex. All

 

 

connections to hubs are not full duplex. This command is available only with

 

 

RSTP operation.

 

 

 

priority

128

This parameter is used by RSTP to determine the port(s) to use for forwarding.

 

(8 as a step value)

The port with the lowest number has the highest priority.

The range is 0 to 240, but you configure the value by entering a multiple of 16. You enter a value in the range 0 - 15. The default value of 128 is derived by the default setting of 8.

Displaying the RSTP configuration (show spanning-tree config) shows 8, but displaying the RSTP operation (show spanning-tree) shows 128.

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