Siemens SIMATIC NET System Manual page 96

Network structures and network configuration
2.3 Media redundancy
Multiple MRP rings
RSTP+ can also be used to connect multiple MRP rings with each other over RSTP. RSTP+
ensures in this case that MRP still manages the ring redundancy without being affected by
RSTP.
RSTP network and two MRP rings with MRP Interconnection
RSTP+ can also connect an RSTP network to two MRP rings that are linked via MRP
Interconnection. In the example topology shown, the two devices RSW1 and RSW4 must
support RSTP+. The devices (RSW2, RSW3, RSW5 and RSW8) involved in the connection
of the two MRP rings must support MRP Interconnection. In addition, the devices RSW2 and
RSW3 must forward BPDUs (Bridge Protocol Data Unit).
The following rules apply to the RSTP+ MRP Interconnection Domain ID in the example
shown:
● The same RSTP+ MRP Interconnection Domain ID must be configured for the devices
RSW1 and RSW4.
● The same RSTP+ MRP Interconnection Domain ID must be configured for the devices
RSW2, RSW3, RSW5 and RSW8.
● The RSTP+ MRP Interconnection Domain ID of the devices RSW1 and RSW4 must differ
from the RSTP+ MRP Interconnection Domain ID of the devices RSW2, RSW3, RSW5
and RSW8.
96
System Manual, 09/2019, C79000-G8976-C242-10
Industrial Ethernet