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   clockdiff    ( 8 )

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Имя (Name)

clockdiff - measure clock difference between hosts

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Синопсис (Synopsis)

clockdiff [-o] [-o1] [--time-format ctime iso] [-V] {destination}

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Описание (Description)

clockdiff Measures clock difference between us and destination with 1 msec resolution using ICMP TIMESTAMP [2] packets or, optionally, IP TIMESTAMP option [3] option added to ICMP ECHO. [1]

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Параметры (Options)

-o
           Use IP TIMESTAMP with ICMP ECHO instead of ICMP TIMESTAMP
           messages. It is useful with some destinations, which do not
           support ICMP TIMESTAMP (f.e. Solaris <2.4).

       -o1
           Slightly different form of -o, namely it uses three-term IP
           TIMESTAMP with prespecified hop addresses instead of four
           term one. What flavor works better depends on target host.
           Particularly, -o is better for Linux.

       -T, --time-format ctime iso
           Print time stamp in output either ISO-8601 format or
           classical ctime format. The ctime format is default. The ISO
           time stamp includes timezone, and is easier to parse.

       -I
           Alias of --time-format iso option and argument.

       -h, --help
           Print help and exit.

       -V, --version
           Print version and exit.

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Предупреждение (Warning)

• Some nodes (Cisco) use non-standard timestamps, which is allowed by RFC, but makes timestamps mostly useless.

• Some nodes generate messed timestamps (Solaris>2.4), when run xntpd. Seems, its IP stack uses a corrupted clock source, which is synchronized to time-of-day clock periodically and jumps randomly making timestamps mostly useless. Good news is that you can use NTP in this case, which is even better.

• clockdiff shows difference in time modulo 24 days.

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Смотри также (See also)

ping(8), arping(8), tracepath(8).

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