A.It is a function used by routing protocols to install routes into routing table
B.It is a function that prevents the advertising of routes over an interface that the router is usingto reach a route
C.Its function is to help avoid routing loops.
D.It is a redistribution technique used by routing protocols

A.An update packet with init flag set from a known， already established neighbor relationship was received by one of the routers.
B.The counters were deleted.
C.The ARP cache was removed.
D.The IP EIGRP neighbor relationship was cleared manually.