| ICMP Types |
|
Type
|
Code
|
Description
|
|
0
|
0
|
Echo
Reply |
|
3
|
|
Destination
Unreachable |
| |
0
|
Network
unreachable |
| |
1
|
Host
unreachable |
| |
2
|
Protocol
unreachable |
| |
3
|
Port
unreachable |
| |
4
|
Fragmentation
needed but DF 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 to TOS |
| |
12
|
Host
unreachable for TOS |
| |
13
|
Communication
administratively prohibited |
| |
14
|
Host
precedence violation |
| |
15
|
Precedence
cutoff in effect |
| 4 |
0
|
Source
quench – gateway requesting the host to reduce transfer rate |
| 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 |
| 8 |
0
|
Echo
request |
| 9 |
0
|
Router
advertisement |
| 10 |
0
|
Router
solicitation |
| 11 |
|
Time
exceeded |
| |
0
|
TTL equals
0 during transit |
| |
1
|
TTL equals
0 during fragment reassembly |
| 12 |
|
Parameter
problem |
| |
0
|
IP header
bad |
| |
1
|
Required
option missing |
| 13 |
0
|
Timestamp
request |
| 14 |
0
|
Timestamp
reply |
| 15 |
0
|
Information
request |
| 16 |
0
|
Information
reply |
| 17 |
0
|
Address
mask request |
| 18 |
0
|
Address
mask reply |