INS_CWGE10FX2TX8MSPOE 02/19/21 PAGE 94
INSTALLATION AND OPERATION MANUAL
CWGE10FX2TX8MSPOE
TECH SUPPORT: 1.888.678.9427
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 STP
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.
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.
