Juniper ACX2000 Configuration Guide

}
protocols {
(mstp | rstp | vstp) {
traceoptions { # Spanning-tree protocol-specific.
file filename <files number> <size bytes> <world-readable | no-world-readable>;
flag flag <flag-modifier> <disable>;
}
}
}
...
Related
Documentation
Layer 2 Control Protocol on ACX Series Routers on page 404•
• Configuring Rapid Spanning-Tree Protocol on page 411
• Configuring Multiple Spanning-Tree Protocol on page 413
• Disabling MSTP on page 417
• Configuring MST Instances on a Physical Interface on page 415
• Configuring VLAN Spanning-Tree Protocol on page 417
Understanding BPDU Protection for Spanning-Tree Instance Interfaces
By default, if a bridge protocol data unit (BPDU) data frame is received on a blocked
interface, the system will disable the interface and stop forwarding frames out the
interface until the interface is explicitly cleared.
The Spanning Tree Protocol (STP) family is designed to break possible loops in a Layer 2
bridged network. Loop prevention avoids damaging broadcast storms that can potentially
render the network useless. STP processes on bridges exchange BPDUs to determine
the LAN topology, decide the root bridge, stop forwarding on some ports, and so on.
However, a misbehaving user application or device can interfere with the operation of
the STP protocols and cause network problems.
On the ACX Series routers, MX Series routers, and EX Series switches only, you can
configure BPDU protection to ignore BPDUs received on interfaces where none should
be expected (for example, a LAN interface on a network edge with no other bridges
present). If a BPDU is received on a blocked interface, the interface is disabled and stops
forwarding frames. By default, all BPDUs are accepted and processed on all interfaces.
You can configure BPDU protection on interfaces with the following encapsulation types:
•
ethernet-bridge
•
ethernet-vpls
•
extended-vlan-bridge
•
vlan-vpls
•
vlan-bridge
•
extended-vlan-vpls
423Copyright © 2017, Juniper Networks, Inc.
Chapter 12: Configuring Layer 2 Control Protocol

Juniper ACX2000 Specifications

General

Brand	Juniper
Model	ACX2000
Category	Network Router
Language	English