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WAGO-ETHERNET-Zubehör 852
Enhanced Features
87
852-1305 8/4-Port 100BASE-T/1000BASE-SX/LX
Manual
1.1.0
7.2.11 Loop Detection
“Loop Detection” handles problems with loops in the network periphery. These
problems can occur if a port is connected to a switch that is in a loop state. A loop
state occurs as a result of user 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 “Loop Detection” function sends probe packets periodically to detect if the
port is connected 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.
Loop Recovery
When “Loop Detection” is enabled, the switch sends a probe packet every two
seconds and waits to receive the packet. If it receives the packet at the same port,
the switch disables the port. After the time period (“Recovery Time”), the switch
enables the port and executes “Loop Detection” again.
The switch generates a “Syslog” (system log), internal log messages and “SNMP
Traps” if it disables a port after “Loop Detection”.