Loop Detection; Cli Configuration - Tripp Lite NGI-M08POE8-L2 Owner's Manual

6.9 Loop Detection

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.
The Switch shuts down a port if the Switch detects that probe 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 listen 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.
6.9.1

CLI Configuration

Node
enable show loop-detection
enable configure terminal
configure loop-detection (disable|enable)
configure loop-detection address
MACADDR
configure no loop-detection address
Command
169
STP
Description
This command displays the current loop
detection configurations.
This command changes the node to configure
node.
This command disables / enables the loop
detection on the switch.
This command configures the destination
MAC for the loop detection special packets.
This command configures the destination
MAC to default (00:0b:04:AA:AA:AB).