ICMP Timestamp Reply
Encyclopedia
The Timestamp Reply is an ICMP
Internet Control Message Protocol
The Internet Control Message Protocol is one of the core protocols of the Internet Protocol Suite. It is chiefly used by the operating systems of networked computers to send error messages indicating, for example, that a requested service is not available or that a host or router could not be...

 message which replies to a Timestamp
ICMP Timestamp
The Timestamp is an ICMP message which is used for time synchronization. It consists of the originating timestamp.Message Format: * Type must be set to 13.* Code must be set to 0....

 message. It consists of the originating timestamp sent by the sender of the Timestamp
ICMP Timestamp
The Timestamp is an ICMP message which is used for time synchronization. It consists of the originating timestamp.Message Format: * Type must be set to 13.* Code must be set to 0....

 as well as a receive timestamp and a transmit timestamp.

Message Format:
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Type = 14 Code = 0 Header Checksum


Identifier


Sequence Number



Originate Timestamp


Receive Timestamp


Transmit Timestamp


  • Type must be set to 14.
  • Code must be set to 0.
  • The Identifier and Sequence Number can be used by the client to match the reply with the request that caused the reply.
  • The data received (a timestamp) in the timestamp
    ICMP Timestamp
    The Timestamp is an ICMP message which is used for time synchronization. It consists of the originating timestamp.Message Format: * Type must be set to 13.* Code must be set to 0....

     is returned in the reply together with two additional timestamps. The timestamp is a 32 bits in length and is then number of milliseconds since midnight UT.

  • The Originate Timestamp is the time the sender last touched the message before sending it, the Receive Timestamp is the time the echoer first touched it on receipt, and the Transmit Timestamp is the time the echoer last touched the message on sending it.

  • If the time is not available in milliseconds or cannot be provided with respect to midnight UT then any time can be inserted in a timestamp provided the high order bit of the timestamp is also set to indicate this non-standard value.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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