Интерактивная система просмотра системных руководств (man-ов)
clockdiff (8)
clockdiff (8) ( Русские man: Команды системного администрирования )
>> clockdiff (8) ( Linux man: Команды системного администрирования )
NAME
clockdiff - measure clock difference between hosts
SYNOPSIS
clockdiff [ -o] [ -o1] destination
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]
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.
WARNINGS
*
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.
