CLOCKDIFF(8) - phpMan

CLOCKDIFF(8)                     System Manager's Manual: iputils                    CLOCKDIFF(8)



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 prespec-
              ified  hop addresses instead of four term one.  What flavor works better depends on
              target host. Particularly, -o is better for Linux.

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

       o 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.

       o clockdiff shows difference in time modulo 24 days.

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

REFERENCES
       [1] ICMP ECHO, RFC0792, page 14.

       [2] ICMP TIMESTAMP, RFC0792, page 16.

       [3] IP TIMESTAMP option, RFC0791, 3.1, page 16.

AUTHOR
       clockdiff was compiled by Alexey Kuznetsov <kuznet AT ms2.ru>. It was  based  on  code
       borrowed  from  BSD  timed  daemon.   It  is  now  maintained  by YOSHIFUJI Hideaki <yosh-
       fuji AT skbuff.net>.

SECURITY
       clockdiff requires CAP_NET_RAW capability to be executed. It is safe to be used as set-uid
       root.

AVAILABILITY
       clockdiff is part of iputils package and the latest versions are  available in source form
       at http://www.skbuff.net/iputils/iputils-current.tar.bz2.



iputils-160308                                                                       CLOCKDIFF(8)

Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache
Under GNU General Public License
2024-04-19 12:13 @18.191.181.231 CrawledBy Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)