| ICMP TYPE | Meaning |
| 0 | Echo reply (ping reply) |
| 3 | Unreachable |
| 4 | Source quench |
| 5 | Redirect |
| 6 | Alternate address |
| 8 | Echo (ping) |
| 9 | Router advertisement |
| 10 | Router-soliticitation |
| 11 | Time exceederd |
| 12 | Parameter problem |
| 13 | Timestamp-reply |
| 14 | Timestamp-request |
| 15 | Information-request |
| 16 | Information-reply |
| 17 | Mask-request |
| 18 | Mask-reply |
| 31 | Conversion error |
| 32 | Mobile-redirect |