Ever wonder what the codes meant for Ping and Traceroute?  Here you go:

Ping Text Characters

Character Description
! 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.

 

IP Traceroute Text Characters

 

Character Description
nn msec For each node, the round-trip time in milliseconds for the specified number of probes
* The probe timed out
A Administratively prohibited (example, access-list)
Q Source quench (destination too busy)
I User interrupted test
U Port unreachable
H Host unreachable
N Network unreachable
P Protocol Unreachable
T Timeout
? Unknown packet type