Allied Telesis AT-S63 - Manual (Page 197)

AT-S63 Management Software Features Guide
Section II: Advanced Operations 197
Guidelines
Here are the guidelines to group link control:
 The switch or stack can support up to eight groups.
 A group can have any number of ports, up to the total number of ports
on the switch.
 Ports can be members of more than one group. Ports can also be
upstream and downstream ports in different groups. Ports, however,
cannot be both upstream and downstream ports in the same group.
 A group that has downstream ports but no upstream ports is
automatically placed in a disabled state, enabling the downstream
ports to forward traffic normally.
 Group link control passes the link states of the upstream ports to the
downstream ports, but not the reverse. Changes to the states of the
downstream ports are not transferred to the upstream ports.
 A group is active as soon as you create it.
 The downstream ports of a new group immediately stop forwarding
traffic if the upstream ports do not have links.
 You cannot prioritize the groups on the switch.