Loop Detection Configuration - Tripp Lite NGI-S04C2 Owner's Manual

4.2.2.

Loop Detection Configuration

Introduction
Loop detection is designed to handle loop problems on the edge of your network. This
can occur when a port is connected to a Switch that is in a loop state. Loop state occurs as
a result of human error. It happens when two ports on a switch are connected with the
same cable. When a switch in loop state sends out broadcast messages the messages loop
back to the switch and are re-broadcast again and again causing a broadcast storm.
The difference between the Loop Detection and STP:
Loop Detection
The loop detection function sends probe packets periodically to detect if the port connect
to a network in loop state.
packets loop back to the same port of the Switch.
Loop Recovery:
When the loop detection is enabled, the Switch will send one probe packets every two
seconds and then wait for this packet. If it receives the packet at the same port, the Switch
will disable this port. After the time period, recovery time, the Switch will enable this port
and do loop detection again.
The Switch generates syslog, internal log messages as well as SNMP traps when it shuts
down a port via the loop detection feature.
For the access Switch, it may not enable the STP function. To guarantee the network
topology is loop free, the Loop detection function also need detect below scenario.
If port 1 and 2 are loop, and port 1's loop detection is enabled, the port 1 will be disabled.
If both of port 1's and port 2's loop detection is enabled, both of port 1 and port 2 will be
disabled.
Default Settings
 The default global Loop-Detection state is disabled.
 The default Loop Detection Destination MAC is 00:0b:04:AA:AA:AB
 The default Port Loop-Detection state is disabled for all ports.
STP
The Switch shuts down a port if the Switch detects that probe
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