Juniper JUNOS OS 10.3 - SOFTWARE Manual page 1673

Meaning
Purpose
Action
Meaning
Related
Documentation
Copyright © 2010, Juniper Networks, Inc.
ge-0/0/0.0 128:513
ge-0/0/1.0 128:514
ge-0/0/2.0 128:515
ge-0/0/3.0 128:516
ge-0/0/4.0 128:517
ge-0/0/5.0 128:518
ge-0/0/6.0 128:519
ge-0/0/7.0 128:520
[output truncated]
The output from the operational mode command
that is a designated port in a forwarding state.
ge-0/0/7.0
Verifying That Root Protection Is Working on the Interface
A configuration change takes place on Switch 4. A smaller bridge priority on the Switch
4 causes it to send superior BPDUs to interface
interface ge-0/0/7 will trigger root protection. Verify that root protection is operating on
interface .
ge-0/0/7
Use the operational mode command:
user@switch> show spanning-tree interface
Spanning tree interface parameters for instance 0
Interface Port ID
ge-0/0/0.0 128:513
ge-0/0/1.0 128:514
ge-0/0/2.0 128:515
ge-0/0/3.0 128:516
ge-0/0/4.0 128:517
ge-0/0/5.0 128:518
ge-0/0/6.0 128:519
ge-0/0/7.0 128:520
(Root—Incon)
[output truncated]
The operational mode command
has transitioned to a loop inconsistent state. The loop inconsistent state
ge-0/0/7.0
makes the interface block and prevents the interface from becoming a candidate for the
root port. When the root bridge no longer receives superior STP BPDUs from the interface,
the interface will recover and transition back to a forwarding state. Recovery is automatic.
Example: Configuring Faster Convergence and Improving Network Stability with RSTP
on EX Series Switches on page 1527
Example: Configuring Loop Protection to Prevent Interfaces from Transitioning from
Blocking to Forwarding in a Spanning Tree on EX Series Switches on page 1569
Example: Configuring BPDU Protection on STP Interfaces to Prevent STP
Miscalculations on EX Series Switches on page 1561
Chapter 65: Examples of Spanning-Tree Protocols Configuration
128:513 32768.0019e2503f00
128:514 32768.0019e2503f00
128:515 32768.0019e2503f00
128:516 32768.0019e2503f00
128:517 32768.0019e2503f00
128:2 16384.00aabbcc0348
128:1 16384.00aabbcc0348
128:520 32768.0019e2503f00
show spanning-tree interface
ge-0/0/7
Designated Designated
port ID bridge ID
128:513 32768.0019e2503f00
128:514 32768.0019e2503f00
128:515 32768.0019e2503f00
128:516 32768.0019e2503f00
128:517 32768.0019e2503f00
128:2 16384.00aabbcc0348
128:1 16384.00aabbcc0348
128:520 32768.0019e2503f00
show spanning-tree interface
20000 BLK DIS
20000 BLK DIS
20000 BLK DIS
20000 FWD DESG
20000 FWD DESG
20000 BLK ALT
20000 FWD ROOT
20000 FWD DESG
shows
. Receipt of superior BPDUs on
Port State Role
Cost
20000 BLK DIS
20000 BLK DIS
20000 BLK DIS
20000 FWD DESG
20000 FWD DESG
20000 BLK ALT
20000 FWD ROOT
20000 BLK DIS
shows that interface
1577