A.Ping verifies the reachability from the local end to the opposite end, it does not mean that the opposite end is reachable from the local end

B.Ping detects the two-way reachability between the correct end and the one-way icmp echo request packet

C.Tracert must be able to trace every hop IP address from source to destination

D.Tracert has the same function as ping, but the name is different

A.R1 is configured with regional authentication

B.The device type of R1 is Level-2

C.The device type of R1 is Level-1

D.R1 has configured the routing domain authentication

A.1001

B.100

C.10000

D.1000

A.TRUE

B.FALSE

A.The hello packet sending interval of Level-1 and Leval-2 of this interface is 3s.

B.The interval for sending Level-1 hello packets on this interface is 5s

C.The interval for sending Level-2 hello packets on this interface is 5s

D.The interval for sending Level-2 CSNP packets of this interface is 5s