Hirschmann RS20 Reference Manual page 171

Redundancy
If you are using the device in a Multiple Spanning Tree (MSTP) environment,
the device only participates in the Common Spanning Tree (CST) instance.
This chapter of the manual also uses the term Global MST instance to
describe this general case.
Parameters Meaning
Tab „CIST" Port configuration and information
on the global MSTI (IST) and the
CST.
Module.Port Port identification using module and
port numbers of the device, e.g. 2.1
for port one of module two.
STP active Here you can switch Spanning Tree
on or off for this port. If Spanning
Tree is activated globally and
switched off at one port, this port
does not send STP-BPDUs and
drops any STP-BPDUs received.
Note: If you want to use other
layer 2 redundancy protocols such
as HIPER-Ring or Ring/Network
coupling in parallel with Spanning
Tree, make sure you switch off the
ports participating in these protocols
in this dialog for Spanning Tree.
Otherwise the redundancy may not
operate as intended or loops can
result.
Port status (read Displays the STP port status with
only) regard to the global MSTI (IST).
Port Role (read Displays the STP port role with
only) regard to the global MSTI (IST).
Table 110:Port-related STP settings and displays, CIST
RM GUI L2E
Release 8.0 05/2013
6.3 Spanning Tree
Possible values
On, Off
discarding, learning,
forwarding, disabled,
manualForwarding,
notParticipate
root
alternate
designated
backup
master
disabled
Default
setting
On
-
-
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