Specifies the format of the ICMP message.

Type Description References

0 Echo reply. RFC 792
1
2
3 Destination unreachable. RFC 792
4 Source quench. RFC 792
5 Redirect. RFC 792
6 Alternate host address.
7
8 Echo request. RFC 792
9 Router advertisement. RFC 1256
10 Router solicitation. RFC 1256
11 Time exceeded. RFC 792
12 Parameter problem. RFC 792
13 Timestamp request. RFC 792
14 Timestamp reply. RFC 792
15 Information request. Obsolete. RFC 792
16 Information reply. Obsolete. RFC 792
17 Address mask request. RFC 950
18 Address mask reply. RFC 950
19 reserved (for security).
20
-
29 reserved (for robustness experiment).
30 Traceroute. RFC 1393
31 Conversion error. RFC 1475
32 Mobile Host Redirect.
33 IPv6 Where-Are-You.
34 IPv6 I-Am-Here.
35 Mobile Registration Request.
36 Mobile Registration Reply.
37 Domain Name request. RFC 1788
38 Domain Name reply. RFC 1788
39 SKIP Algorithm Discovery Protocol.
40 Photuris, Security failures. RFC 2521
41 Experimental mobility protocols. RFC 4065
42

55 Reserved.