Hirschmann RS20 User Manual page 134

Network load control
Figure 38: Defining the VLAN membership of the ports.
Ports 1.1 to 1.3 are assigned to the terminal devices of the Yellow
VLAN, and ports 2.1 to 2.4 are assigned to terminal devices of the
Green VLAN. Because terminal devices usually do not sent data pack-
ets with a tag, you select the U setting here.
Port 1.4 functions as the uplink port to the next device. It is assigned the
setting M. Thus it can forward VLAN information.
134
7.6 VLANs
Basic Configuration L2P
Release 4.2 07/08