Juniper JUNOS OS 10.3 - SOFTWARE Manual page 1669

Action
Meaning
Related
Documentation
Example: Configuring Root Protection to Enforce Root Bridge Placement in Spanning
Trees on EX Series Switches
Copyright © 2010, Juniper Networks, Inc.
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
(Loop-Incon)
[output truncated]
The operational mode command
has detected that BPDUs are no longer being forwarded to it and has moved
ge-0/0/6.0
into a loop-inconsistent state. The loop-inconsistent state prevents the interface from
transitioning to a forwarding state. The interface recovers and transitions back to its
original state as soon as it receives BPDUs.
Example: Configuring Faster Convergence and Improving Network Stability with RSTP
on EX Series Switches on page 1527
Example: Configuring Root Protection to Enforce Root Bridge Placement in Spanning
Trees on EX Series Switches on page 1573
Example: Configuring BPDU Protection on STP Interfaces to Prevent STP
Miscalculations on EX Series Switches on page 1561
Example: Configuring BPDU Protection on non-STP Interfaces to Prevent STP
Miscalculations on EX Series Switches on page 1565
Understanding Loop Protection for STP, RSTP, VSTP, and MSTP on EX Series Switches
on page 1523
EX Series switches provide Layer 2 loop prevention through Spanning Tree Protocol
(STP), Rapid Spanning Tree protocol (RSTP), and Multiple Spanning Tree Protocol
(MSTP). Root protection increases the efficiency of STP, RSTP, and MSTP by allowing
network administrators to manually enforce the root bridge placement in the network.
This example describes how to configure root protection on an interface on an EX Series
switch:
Requirements on page 1574
Overview and Topology on page 1574
Chapter 65: Examples of Spanning-Tree Protocols Configuration
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
128:518 32768.0019e2503f00
128:519 32768.0019e2503f00
show spanning-tree interface
Port State Role
Cost
20000 BLK DIS
20000 BLK DIS
20000 BLK DIS
20000 FWD DESG
20000 FWD DESG
20000 FWD DESG
20000 BLK DIS
shows that interface
1573