ICMP type codes are registered with the IANA. The information presented here is reproduced with permission from the IANA. For the most current ICMP type code number assignment information, refer to www.iana.org/numbers.htm under the "ICMP Type" link.
Table B-2 shows the assigned ICMP type numbers, ICMP codes (where applicable), a brief description, and a reference to an RFC.
Table B-2. Assigned ICMP Type Numbers, Codes, Descriptions, and Associated RFCs
Type | Code | Name | Reference |
---|
0 | | Echo Reply | RFC 792 |
1 | | Unassigned | |
2 | | Unassigned | |
3 | | Destination Unreachable | RFC 792 |
| 0 | Net Unreachable | |
| 1 | Host Unreachable | |
| 2 | Protocol Unreachable | |
| 3 | Port Unreachable | |
| 4 | Fragmentation Needed and Don't Fragment Was Set | |
| 5 | Source Route Failed | |
| 6 | Destination Network Unknown | |
| 7 | Destination Host Unknown | |
| 8 | Source Host Isolated | |
| 9 | Destination Network Is Administratively Prohibited | |
| 10 | Destination Host Is Administratively Prohibited | |
| 11 | Destination Network Unreachable for Type of Service | |
| 12 | Destination Host Unreachable for Type of Service | |
| 13 | Communication Administratively Prohibited | RFC 1812 |
| 14 | Host Precedence Violation | RFC 1812 |
| 15 | Precedence Cutoff in Effect | RFC 1812 |
4 | | Source Quench | RFC 792 |
5 | | Redirect | RFC 792 |
| 0 | Redirect Datagram for the Network (or Subnet) | |
| 1 | Redirect Datagram for the Host | |
| 2 | Redirect Datagram for the Type of Service and Network | |
| 3 | Redirect Datagram for the Type of Service and Host | |
6 | | Alternate Host Address | |
| 0 | Alternate Address for Host | |
7 | | Unassigned | |
8 | | Echo | RFC 792 |
9 | | Router Advertisement | RFC 1256 |
10 | | Router Solicitation | RFC 1256 |
11 | | Time Exceeded | RFC 792 |
| 0 | Time to Live Exceeded in Transit | |
| 1 | Fragment Reassembly Time Exceeded | |
12 | | Parameter Problem | RFC 792 |
| 0 | Pointer Indicates the Error | |
| 1 | Missing a Required Option | RFC 1108 |
| 2 | Bad Length | |
13 | | Timestamp | RFC 792 |
14 | | Timestamp Reply | RFC 792 |
15 | | Information Request | RFC 792 |
16 | | Information Reply | RFC 792 |
17 | | Address Mask Request | RFC 950 |
18 | | Address Mask Reply | RFC 950 |
19 | | Reserved (for Security) | |
20 to 29 | | Reserved (for Robustness Experiment) | |
30 | | Traceroute | RFC 1393 |
31 | | Datagram 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 | |
38 | | Domain Name Reply | |
39 | | SKIP | |
40 | | Photuris | |
| 0 | Reserved | |
| 1 | Unknown Security Parameters Index | |
| 2 | Valid Security Parameters, but Authentication Failed | |
| 3 | Valid Security Parameters, but Decryption Failed | |
41 to 255 | | Reserved | |