S
PANNING
T
REE
C
OMMANDS
3-119
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
• This command is used to enable/disable the fast spanning-tree
mode for the selected port. In this mode, ports skip the
Blocked, Listening and Learning states and proceed straight to
Forwarding.
• Since end-nodes cannot cause forwarding loops, they can be
passed through the spanning tree state changes more quickly
than allowed by standard convergence time. Fast forwarding
can achieve quicker convergence for end-node workstations
and servers, and also overcome other STA related timeout
problems. (Remember that fast forwarding should only be
enabled for ports connected to an end-node device.)
Example
show spanning-tree
Use this command to show the spanning tree configuration.
Syntax
show spanning-tree [interface]
interface
•ethernet unit/port
-unit - This is device 1.
-port - Port number.
•port-channel channel-id (Range: 1-4)
Default Setting
None
Console(config)#interface ethernet 1/5
Console(config-if)#spanning-tree portfast
Console(config-if)#