Ping avec heure

                                                          September 1981
Internet Protocol
Specification



      Internet Timestamp

        +--------+--------+--------+--------+
        |01000100| length | pointer|oflw|flg|
        +--------+--------+--------+--------+
        |         internet address          |
        +--------+--------+--------+--------+
        |             timestamp             |
        +--------+--------+--------+--------+
        |                 .                 |
                          .
                          .
        Type = 68

        The Option Length is the number of octets in the option counting
        the type, length, pointer, and overflow/flag octets (maximum
        length 40).

        The Pointer is the number of octets from the beginning of this
        option to the end of timestamps plus one (i.e., it points to the
        octet beginning the space for next timestamp).  The smallest
        legal value is 5.  The timestamp area is full when the pointer
        is greater than the length.

        The Overflow (oflw) [4 bits] is the number of IP modules that
        cannot register timestamps due to lack of space.

        The Flag (flg) [4 bits] values are

          0 -- time stamps only, stored in consecutive 32-bit words,

          1 -- each timestamp is preceded with internet address of the
               registering entity,

          3 -- the internet address fields are prespecified.  An IP
               module only registers its timestamp if it matches its own
               address with the next specified internet address.

        The Timestamp is a right-justified, 32-bit timestamp in
        milliseconds since midnight UT.  If the time is not available in
        milliseconds or cannot be provided with respect to midnight UT
        then any time may be inserted as a timestamp provided the high
        order bit of the timestamp field is set to one to indicate the
        use of a non-standard value.

        The originating host must compose this option with a large
        enough timestamp data area to hold all the timestamp information
        expected.  The size of the option does not change due to adding


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