[Appendix F] F.3 ICMP Parameter Problem Message Header
Author: Craig Hunt
Date: 1999-02-04T01:46:35Z

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| Appendix F Selected TCP/IP Headers |

## F.3 ICMP Parameter Problem Message Header

This description is taken from pages 8 and 9 of RFC 792, Internet Control Message Protocol, by Jon Postel, Information Sciences Institute, University of Southern California.

>     Parameter Problem Message

>         0                   1                   2                   3
>         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
>        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>        |     Type      |     Code      |          Checksum             |
>        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>        |    Pointer    |                   unused                      |
>        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>        |      Internet Header + 64 bits of Original Data Datagram      |
>        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

>        Type

>           12

>        Code

>           0 = pointer indicates the error.

>        Checksum

>           The checksum is the 16-bit ones's complement of the one's
>           complement sum of the ICMP message starting with the ICMP Type.
>           For computing the checksum , the checksum field should be zero.

>        Pointer

>           If code = 0, identifies the octet where an error was detected.

>        Internet Header + 64 bits of Data Datagram

>           The internet header plus the first 64 bits of the datagram that
>           elicited this error response.

F.2 TCP Segment Header |  |