Hirschmann RS20 Reference Manual page 154

Redundancy 6.1 Ring Redundancy
Figure 43: Selecting MRP-Ring version, entering ring ports and enabling/disabling
ring manager
Note: For all devices in an MRP-Ring, activate the MRP compatibility in the
Redundancy:Spanning Tree:Global dialog if you want to use RSTP in
the MRP-Ring. If this is not possible, perhaps because individual devices do
not support the MRP compatibility, you deactivate the Spanning Tree
protocol on the ports connected to the MRP-Ring. Spanning Tree and Ring
Redundancy affect each other.
Note: If you combine RSTP with an MRP-Ring, you must give the devices in
the MRP-Ring a better (i.e. numerically lower) RSTP bridge priority than the
devices in the connected RSTP network. You thus help avoid a connection
interruption for devices outside the Ring.
RM GUI L2E
154
Release 8.0 05/2013