This section describes the definition and purpose of link-group.
A link-group is used to bind the state of several physical interfaces to form a logical group. If one of the interfaces within the logical group is faulty, the system sets the state of the other interfaces as Down. After all the interfaces are functional, the system resets the state of the interfaces within the logical group as Up.
The Link-group management group ensures the status consistency of the physical interfaces in the group, and accelerates the route convergence when the link is faulty.