Vlan Settings (Virtual Local Area Network) - D-Link DGS-1224T Manual

QoS:
In some ports that need to have a high priority to manage the data
transfer, QoS should be change. Set the port's QoS to high to
determine the port will always transfer their data first.

VLAN Settings (Virtual Local Area Network)

Group individual ports into a small "Virtual" network of their own to
be independent of the other ports. To add a VLAN group, press "Add
Group" button, the new VLAN configuration window will pop out,
you can fill in the description in order to describe this VLAN Group,
check on the port to be a member to thi s VLAN Group, and press
"Apply" button to execute the setting.
Figure 19. VLAN Group Settings
Once you want to modify the VLAN Group, check on the ID
parameter, the ID VLAN configuration window will pop out.
Figure 20. VLAN Settings
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