August 2003
Intermediate to advanced
320 pages
10h 14m
English
Content preview from Practical TCP/IP and Ethernet Networking for Industry
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132 Practical TCP/IP and Ethernet Networking
Checksum: 16 bits
This is the 16-bit one’s complement of the one’s complement sum of a pseudo header
of information from the IP header, the UDP header, and the data, padded with ‘0’ bytes at
the end (if necessary) to make a multiple of two bytes.
The pseudo header, conceptually prefixed to the UDP header, contains the source
address, the destination address, the protocol, and the UDP length. As in the case of TCP,
this header is used for computational purposes only, and is NOT transmitted. This
information gives protection against misrouted datagrams. This checksum procedure is
the same as is used ...