Hirschmann GREYHOUND GRS1020, Reference Manual

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Operation diagnosis
13.10 Detecting loops
209
UM Config GRS
Release 8.0 09/2019
13.10 Detecting loops
Loops in the network cause connection interruptions or data losses. This also applies to temporary
loops. The automatic detection and reporting of this situation lets you detect it faster and diagnose
it more easily.
An incorrect configuration causes loops, for example, deactivating Spanning Tree.
The device lets you detect the effects typically caused by loops and report this situation
automatically to the network management station. You have the option here to specify the
magnitude of the loop effects that trigger the device to send a report.
BPDU frames sent from the designated port and received on either a different port of the same
device or the same port within a short time, is a typical effect of a loop.

Open the
Switching > L2-Redundancy > Spanning Tree > Port
dialog,
CIST
tab.

Check the value in the fields
Port state
and
Port role
. If the
Port state
field displays the value
discarding and the
Port role
field displays the value backup , then the port is in a loop
status.
or

Open the
Switching > L2-Redundancy > Spanning Tree > Port
dialog,
Guards
tab.

Check the value in the
Loop state
column. If the field displays the value true , then the port
is in a loop status.