火柴 Tips 3

Protocol [ip]:
Target IP address: 10.0.10.2
Repeat count [5]:50
Datagram size [100]: 1000
Timeout in seconds [2]:
Extended commands [n]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 5, 1000-byte ICMP Echoes to 10.0.10.2, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!....................UU......!!!!!!!!!!!!!!...........U.U!!!!
Success rate is 68 percent (50/50), round-trip min/avg/max = 320/302/232 ms

1) What does the exclamation point (!) indicate?
2) What does the exclamation point (.) indicate?
3) What does the exclamation point (U) indicate?
4) What does the ping test for?