Hirschmann RS20 User Manual page 136

Network Load Control
Note: If the device is incorporated into a HIPER-Ring, you can use the
following settings to quickly reconfigure the network for data packets
with registered Multicast destination addresses after the ring is
switched:
Activate GMRP on the ring ports and globally, and
activate "Forward all groups" on the ring ports.
136
8.2 Multicast Application
Basic Configuration
Release 6.0 07/2010