The Echo Request is an ICMP message which sends a packet of data to the host and expects that data to be sent in return in a Echo Reply. The host must respond to all Echo Requests with an Echo Reply containing the exact data received in the request message.
Message Format:
| 00 |
01 |
02 |
03 |
04 |
05 |
06 |
07 |
08 |
09 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
27 |
28 |
29 |
30 |
31 |
| Type = 8 |
Code = 0 |
Header Checksum |
|
Identifier |
<p align="center">Sequence Number |
</table>
|
Data ::: |
</table>
- Type must be set to 8.
- Code must be set to 0.
- The Identifier and Sequence Number can be used by the client to match the reply with the request that caused the reply.
- The data received by the Echo Request must be entirely included in the Echo Reply.
See also
