Users Guide

Port 289 (TenGigabitEthernet 2/1) is Forwarding
Port path cost 4, Port priority 8, Port Identifier 8.289
Designated root has priority 32768, address 0001.e80d.2462
Designated bridge has priority 32768, address 0001.e80d.2462
Designated port id is 8.496, designated path cost 0
Timers: message age 1, forward delay 0, hold 0
Number of transitions to forwarding state 1
BPDU: sent 21, received 486
The port is not in the portfast mode
Port 290 (TenGigabitEthernet 2/2) is Blocking
Port path cost 4, Port priority 8, Port Identifier 8.290
--More--
Timers: message age 1, forward delay 0, hold 0
Number of transitions to forwarding state 1
BPDU: sent 21, received 486
The port is not in the portfast mode
To confirm that a port is participating in Spanning Tree, use the show spanning-tree 0 brief command from EXEC privilege
mode.
Dell#show spanning-tree 0 brief
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 32768, Address 0001.e80d.2462
We are the root of the spanning tree
Root Bridge hello time 2, max age 20, forward delay 15
Bridge ID Priority 32768, Address 0001.e80d.2462
Configured hello time 2, max age 20, forward delay 15
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
-------------- ------ ---- ---- --- ----- --------------------
Te 1/1 8.496 8 4 DIS 0 32768 0001.e80d.2462 8.496
Te 1/2 8.497 8 4 DIS 0 32768 0001.e80d.2462 8.497
Te 1/3 8.513 8 4 FWD 0 32768 0001.e80d.2462 8.513
Te 1/4 8.514 8 4 FWD 0 32768 0001.e80d.2462 8.514
Dell#
Adding an Interface to the Spanning Tree Group
To add a Layer 2 interface to the spanning tree topology, use the following command.
• Enable spanning tree on a Layer 2 interface.
INTERFACE mode
spanning-tree 0
Modifying Global Parameters
You can modify the spanning tree parameters. The root bridge sets the values for forward-delay, hello-time, and max-age and overwrites
the values set on other bridges participating in STP.
NOTE:
Dell Networking recommends that only experienced network administrators change the spanning tree
parameters. Poorly planned modification of the spanning tree parameters can negatively affect network performance.
The following table displays the default values for STP.
Table 92. STP Default Values
STP Parameters Default Value
Forward Delay 15 seconds
Hello Time 2 seconds
Max Age 20 seconds
Port Cost
• 200000
Spanning Tree Protocol (STP) 775