Reference Guide

Spanning Tree Protocol (STP) | 1473
spanning-tree 0
c e s
Assigns a Layer 2 interface to STP instance 0 and configures a port cost or port
priority, or enables loop guard, root guard, or the Portfast feature on the interface.
Syntax
spanning-tree stp-id {cost cost | {loopguard | rootguard} |
portfast
[bpduguard [shutdown-on-violation]] | priority priority}
To disable Spanning Tree group on an interface, use the
no spanning-tree stp-id
{
cost cost | {loopguard | rootguard} | portfast [bpduguard
[shutdown-on-violation]] | priority priority} command.
Parameters
Defaults
cost
= depends on the interface type; priority = 8
Sts Port state: root-inconsistent (INCON Root), forwarding (FWD), listening
(LIS), blocking (BLK), or shut down (EDS Shut)
Guard Type Type of STP guard configured (Root, Loop, or BPDU guard)
Table 52-2. show spanning-tree 0 guard Command Example Information
Field Description
stp-id Enter the STP instance ID. Range: 0
cost cost Enter the keyword
cost followed by a number as the cost.
Range: 1 to 65535
Defaults:
• 100 Mb/s Ethernet interface = 19
• 1-Gigabit Ethernet interface = 4
• 10-Gigabit Ethernet interface = 2
• Port Channel interface with 100 Mb/s Ethernet = 18
• Port Channel interface with 1-Gigabit Ethernet = 3
• Port Channel interface with 10-Gigabit Ethernet = 1
loopguard (C-, S-, and E-Series TeraScale S4810 and S4820T only) Enter the keyword
loopguard to enable STP loop guard on a port or port-channel interface.
rootguard (C-, S-, and E-Series TeraScale S4810 and S4820T only) Enter the keyword
rootguard to enable STP root guard on a port or port-channel interface.
portfast
[bpdugu
ard
[shutdo
wn-on-v
iolation]
]
Enter the keyword portfast to enable Portfast to move the interface into
forwarding mode immediately after the root fails.
Enter the optional keyword bpduguard to disable the port when it receives a
BPDU.
Enter the optional keyword
shutdown-on-violation to hardware disable an
interface when a BPDU is received and the port is disabled.
priority priority Enter keyword priority followed by a number as the priority.
Range: zero (0) to 15
Default: 8