Figure 48: Network Topology For Loop Protection - Juniper JUNOS OS 10.4 - FOR EX REV 1 Manual

Complete Software Guide for Junos
Table 257: Components of the Topology for Configuring Loop Protection on EX Series Switches
Property
Switch 1
Switch 2
Switch 3
1804
®
OS for EX Series Ethernet Switches, Release 10.4
Loops in a Layer 2 topology cause broadcast, unicast, and multicast frames to
continuously circle the looped network. As a switch processes a flood of frames in a
looped network, its resources become depleted and the ultimate result is a network
outage.
CAUTION: An interface can be configured for either loop protection or root
protection, but not for both.
Three EX Series switches are displayed in Figure 48 on page 1804. In this example, they are
configured for RSTP and create a loop-free topology. Interface
traffic between Switch 3 and Switch 1; thus, traffic is forwarded through interface
on Switch 2. BPDUs are being sent from the root bridge on Switch 1 to both of these
interfaces.
This example shows how to configure loop protection on interface
it from transitioning from a blocking state to a forwarding state and creating a loop in
the spanning-tree topology.

Figure 48: Network Topology for Loop Protection

Table 257 on page 1804 shows the components that will be configured for loop protection.
Settings
Switch 1 is the root bridge.
Switch 2 has the root port
Switch 3 is connected to Switch 1 through interface
ge-0/0/6
.
ge-0/0/7
ge-0/0/6
Copyright © 2010, Juniper Networks, Inc.
is blocking
ge-0/0/7
ge-0/0/6 to prevent
.