Users Guide
22
ICMP Message Types
This chapter lists and describes the possible ICMP message type resulting from a ping. The rst three columns list the possible 
symbol or type/code. For example, you would receive a ! or 03 as an echo reply from your ping.
ICMP Messages and Their Denitions.
Symbol Type Code Description Query Error
.  Timeout (no reply)
! 0 3 echo reply . 
U 3 destination unreachable:
0 network unreachable . 
1 host unreachable . 
2 protocol unreachable . 
3 port unreachable . 
4 fragmentation needed but don’t fragment bit 
set
. 
5 source route failed . 
6 destination network unknown . 
7 destination host unknown . 
8 source host isolated (obsolete) . 
9 destination network administratively 
prohibited
. 
10 destination host administratively prohibited . 
11 network unreachable for TOS . 
12 host unreachable for TOS . 
13 communication administratively prohibited by 
ltering
. 
14 host precedence violation . 
15 precedence cuto in eect . 
C 4 0 source quench . 
5 redirect . 
0 redirect for network . 
1 redirect for host . 
2 redirect for type-of-service and network . 
3 redirect for type-of-service and host . 
ICMP Message Types
633










