System information

2-34
Configuring the Switch
2
CLI – This command displays global STA settings, followed by settings for each
port.
Note: The current root port and current root cost display as zero when this device is not
connected to the network.
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.
• 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
Console#show spanning-tree 3-81
Bridge-group information
--------------------------------------------------------------
Spanning tree protocol :IEEE Std 8021D
Spanning tree enable/disable :enable
Priority :32768
Hello Time (sec.) :2
Max Age (sec.) :20
Forward Delay (sec.) :15
Designated Root :32768.0030f147583a
Current root port :0
Current root cost :0
Number of topology changes :1
Last topology changes time (sec.):26696
Hold times (sec.) :1
---------------------------------------------------------------
Eth 1/ 1 information
--------------------------------------------------------------
Admin status : enable
STA state : broken
Path cost : 18
Priority : 128
Designated cost : 0
Designated port : 128.1
Designated root : 32768.0030f147583a
Designated bridge : 32768.0030f147583a
Fast forwarding : disable
Forward transitions : 0
...