A.A successor route is used by EIGRP to forward traffic to a destination.
B.Successor routes are saved in the topology table to be used if the primary route fails.
C.Successor routes are flagged as "active" in the routing table.
D.A successor route may be backed up by a feasible successor route.
E.Successor routes are stored in the neighbor table following the discovery process.

A.Switch1（config-if）# switchport port-security maximum 1
B.Switch1（config）# mac-address-table secure
C.Switch1（config）# access-list 10 permit ip host
D.Switch1（config-if）# switchport port-security violation shutdown
E.Switch1（config-if）# ip access-group 10