Name
Checksum
Synopsis
Used to store a checksum of the ICMP message, allowing destination systems to validate the contents of the message and test for possible corruption.
- Size
Sixteen bits.
- Notes
The checksum field provides a simple validation scheme for ICMP messages. When calculating the checksum, the sending system looks at the entire message (with the checksum field set to 0) and performs a simple checksum operation. This procedure is reversed by all recipients before the contents of the message are processed.
- Capture Sample
In the capture shown in Figure 5.24, the Checksum has been calculated to hexadecimal “89 07”, which is correct.
Figure 5.24. The Checksum field
Get Internet Core Protocols: The Definitive Guide now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
