clockdiff man page on Oracle

Man page or keyword search:  
man Server   33470 pages
apropos Keyword Search (all sections)
Output format
Oracle logo
[printable version]

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

       clockdiff - measure clock difference between hosts

       clockdiff [-o] [-o1] destination

       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]

       -o     Use  IP  TIMESTAMP with ICMP ECHO instead of ICMP TIMESTAMP mes‐
	      sages. 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. Particu‐
	      larly, -o is better for Linux.

       · 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  synchro‐
	 nized	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.

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

       [1] ICMP ECHO, RFC0792, page 14.

       [2] ICMP TIMESTAMP, RFC0792, page 16.

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

       clockdiff  was  compiled by Alexey Kuznetsov <>. It
       was based on code borrowed from BSD timed daemon.  It is now maintained
       by YOSHIFUJI Hideaki <>.

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

       clockdiff is part of  iputils  package  and  the	 latest	 versions  are
       available  in source form at‐

iputils-121221			  02 May 2014			  CLOCKDIFF(8)

List of man pages available for Oracle

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net