Spanning Tree Algorithm Configuration

3

CLI – This example shows the STA attributes for port 5.

 

 

 

 

 

Console#show spanning-tree

ethernet 1/5

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Eth 1/ 5 information

 

 

 

--------------------------------------------------------------

 

 

Admin status:

enabled

 

 

Role:

disable

 

 

State:

discarding

 

 

External admin path cost:

1000

 

 

Internal admin cost:

1000

 

 

External oper path cost:

1000

 

 

Internal oper path cost:

1000

 

 

Priority:

128

 

 

Designated cost:

0

 

 

Designated port:

128.5

 

 

Designated root:

32768.0.0000E8AAAA00

 

 

Designated bridge:

32768.0.0030F1D473A0

 

 

Fast forwarding:

disabled

 

 

Forward transitions:

2

 

 

Admin edge port:

disabled

 

 

Oper edge port:

disabled

 

 

Admin Link type:

auto

 

 

Oper Link type:

point-to-point

 

 

Spanning Tree Status:

enabled

 

 

Console#

 

 

 

 

 

 

 

Configuring Interface Settings

You can configure RSTP and MSTP attributes for specific interfaces, including port priority, path cost, link type, and edge port. You may use a different priority or path cost for ports of the same media type to indicate the preferred path, link type to indicate a point-to-point connection or shared-media connection, and edge port to indicate if the attached device can support fast forwarding. (References to “ports” in this section means “interfaces,” which includes both ports and trunks.)

Command Attributes

The following attributes are read-only and cannot be changed:

•Port – Port identifier. (Range: 1-8)

•STA State – Displays current state of this port within the Spanning Tree. (See Displaying Interface Settings on page 3-120for additional information.)

•Discarding - Port receives STA configuration messages, but does not forward packets.

•Learning - Port has transmitted configuration messages for an interval set by the Forward Delay parameter without receiving contradictory information. Port address table is cleared, and the port begins learning addresses.

•Forwarding - Port forwards packets, and continues learning addresses.

•Trunk16 – Indicates if a port is a member of a trunk.

16. STA Port Configuration only

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