ICMP Timestamp
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The Timestamp is an ICMP message which is used for time synchronization. It consists of the originating 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 = 13 | Code = 0 | Header Checksum |
|
Identifier |
Sequence Number |
|
Originate Timestamp |
- Type must be set to 13.
- Code must be set to 0.
- The Identifier and Sequence Number can be used by the client to match the timestamp reply with the timestamp request.
- The data transmitted (originate timestamp) in the timestamp is 32 bits in length and is the number of milliseconds since midnight UT.
- 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.
