ntp(n)								 Tnm Tcl Extension							    ntp(n)

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NAME

       ntp - Retrieve NTP status information.
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DESCRIPTION

       The  Network  Time  Protocol  (NTP)  (RFC 1119, RFC 1305) allows to synchronize computer clocks by exchanging NTP messages. The ntp command
       allows to retrieve control variables from NTP peers.

NTP COMMAND

       ntp [options]
	      Invoking the ntp command with options but without any command arguments allows to retrieve and change the default  values.  See  the
	      description  of supported options below. Default values are bound to a Tcl interpreter which allows to have multiple Tcl interpreter
	      with different defaults.

       ntp [options] host arrayName
	      The ntp command sends a NTP version 3 mode 6 request to host and writes status information into the Tcl array arrayName. After  suc-
	      cessful completion, the array will contain the following elements (RFC 1305):

	      peer.delay
		     This  is  a  signed  fixed-point number indicating the roundtrip delay of the peer clock relative to the local clock over the
		     network path between them, in seconds.

	      peer.dispersion
		     This is a signed fixed-point number indicating the maximum error of the peer clock relative to the local clock over the  net-
		     work path between them, in seconds.

	      peer.offset
		     This is a signed, fixed-point number indicating the offset of the peer clock relative to the local clock, in seconds.

	      peer.precision
		     This is a signed integer indicating the precision of the various clocks, in seconds to the nearest power of two.

	      peer.reach
		     This is a shift register used to determine the reachability status of the peer, with bits entering from the least significant
		     (rightmost) end. A peer is considered reachable if at least one bit in this register is set to one.

	      peer.srcadr
		     This is the IP address of the peer.

	      peer.stratum
		     This is an integer indicating the stratum of the local clock.

	      peer.valid
		     This is an integer counter indicating the valid samples remaining in the filter register. It is used to determine the reacha-
		     bility state and when the poll interval should be increased or decreased.

	      sys.peer
		     This is a selector identifying the current synchronization source.

	      sys.precision
		     This is a signed integer indicating the precision of the various clocks, in seconds to the nearest power of two.

	      sys.refid
		     This is a 32-bit code identifying the particular reference clock.

	      sys.rootdelay
		     This  is  a signed fixed-point number indicating the total roundtrip delay to the primary reference source at the root of the
		     synchronization subnet, in seconds.

	      sys.rootdispersion
		     This is a signed fixed-point number indicating the maximum error relative to the primary reference source at the root of  the
		     synchronization subnet, in seconds.

	      sys.stratum
		     This is an integer indicating the stratum of the local clock

	      sys.system
		     A textual description of the system type.

NTP OPTIONS

       The following options control how NTP requests are send and how the ntp command deals with lost NTP packets.

       -timeout time
	      The  -timeout  option  defines the time the ntp command will wait for a response. The time is defined in seconds with a default of 2
	      seconds.

       -retries number
	      The -retries option defines how many times a request is retransmitted during the timeout interval. The default number of retries	is
	      2.

SEE ALSO

       scotty(1), Tnm(n), Tcl(n)

AUTHORS

       Erik Schoenfelder <schoenfr@gaertner.de>
       Juergen Schoenwaelder <schoenw@cs.utwente.nl>

Tnm																	    ntp(n)