Ping cisco ios

When using Cisco IOS to ping, single character response codes are shown on-screen.

R1#<input>ping 172.16.4.17</input>

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.4.17, timeout is 2 seconds:
<notice>!.U!.</notice>
Success rate is 40 percent (2/5), round-trip min/avg/max = 1/2/8 ms

Ping character explanations

Cisco ping response characters

Character	Explanation
!	Each exclamation point indicates receipt of a reply
.	Each period indicates the network server timed out while waiting for a reply
U	A destination unreachable error PDU was received
Q	Source quench (destination too busy)
M	Could not fragment
?	Unknown packet type
&	Packet lifetime exceeded