Administrator Guide

Version Description
8.5.1.0 Added support for 4-port 40G line cards on the E-Series.
8.4.2.1 Added support for the optional guard keyword on the C-Series, S-Series, and E-Series.
8.3.7.0 Introduced on the S4810.
7.7.1.0 Introduced on the S-Series.
7.5.1.0 Introduced on the C-Series.
6.2.1.1 Introduced on the E-Series.
Usage Information Enable spanning tree group 0 prior to using this command.
The following describes the show spanning-tree 0 command shown in the example.
Field Description
“Bridge
Identifier...”
Lists the bridge priority and the MAC address for this STP bridge.
“Configured
hello...”
Displays the settings for hello time, max age, and forward delay.
“We are...” States whether this bridge is the root bridge for the STG.
“Current root...” Lists the bridge priority and MAC address for the root bridge.
“Topology flag...” States whether the topology flag and the detected flag were set.
“Number of...” Displays the number of topology changes, the time of the last topology change, and on
what interface the topology change occurred.
“Timers” Lists the values for the following bridge timers: hold time, topology change, hello time,
max age, and forward delay.
“Times” List the number of seconds since the last:
• hello time
• topology change
• notification
• aging
“Port 1...” Displays the Interface type slot/port information and the status of the interface (Disabled
or Enabled).
“Port path...” Displays the path cost, priority, and identifier for the interface.
“Designated
root...”
Displays the priority and MAC address of the root bridge of the STG that the interface
belongs.
“Designated
port...”
Displays the designated port ID.
Example
DellEMC# show spann 0
Executing IEEE compatible Spanning Tree Protocol
Bridge Identifier has priority 32768, Address 0001.e800.0a56
Configured hello time 2, max age 20, forward delay 15
We are the root of the spanning tree
Current root has priority 32768 address 0001.e800.0a56
Topology change flag set, detected flag set
Number of topology changes 1 last change occurred 0:00:05 ago
from GigabitEthernet 1/3
Timers:hold 1, topology change 35
hello 2, max age 20, forward_delay 15
Times:hello 1, topology change 1, notification 0, aging 2
Port 26 (GigabitEthernet 1/1) is Forwarding
Port path cost 4, Port priority 8, Port Identifier 8.26
Spanning Tree Protocol (STP) 1493