Dell PowerConnect 7048P Manual page 485

You can create a maximum of 72 dependency groups16 groups. The ports
participating in the Link Dependency can be across all the Stack Units
(Manager/Member unit).
Link Action
The link action specifies the action that the group members will take when
the dependent port is down. The group members can transition to the same
state as the dependant port, or they can transition to the opposite state. In
other words, if the link action is down and the dependent port goes down, the
members ports will go down as well. Conversely, when the link action is up
and the dependant link goes down, the group member ports are enabled
(brought up).
Creating a link dependency group with the up link action essentially creates a
backup link for the dependent link and alleviates the need to implement STP
to handle the fail-over.
Link Dependency Scenarios
The Link Dependency feature supports the scenarios in the following list.
NOTE:
Whether the member ports or LAGs are brought
the link action.
• Port dependent on port — If a port loses the link, the switch brings
up/down the link on another port.
• Port dependent on LAG — If all ports in a channel-group lose the link, the
switch brings up/down the link on another port.
• LAG dependent on port — If a port loses the link, the switch brings
up/down all links in a channel-group.
• Multiple port command — If a group of ports lose their link, the switch
brings up/down the link on another group of ports.
• Overlapping ports — Overlapping ports on different groups will be
brought up/down only if both dependent ports lose the link.
up
Configuring Port Characteristics
down
or depends on
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