Comments on: Testing for TCP/IP Timestamps https://www.exploresecurity.com/testing-for-tcp-ip-timestamps/ IT security tools, techniques and commentary Sun, 07 Sep 2025 03:12:25 +0000 hourly 1 http://wordpress.org/?v=3.6.1 By: Trias https://www.exploresecurity.com/testing-for-tcp-ip-timestamps/#comment-14876 Trias Thu, 04 May 2017 18:43:14 +0000 http://www.exploresecurity.com/?p=261#comment-14876 Timestamp Echo Reply (TSecr). 32 bits.
This field is only valid if the ACK bit is set in the TCP header. If it is valid, it echos a timestamp value that was sent by the remote TCP in the TSval field of a Timestamps option. When TSecr is not valid, its value must be zero. The TSecr value will generally be from the most recent Timestamp option that was received; however, there are exceptions that are explained below. A TCP may send the Timestamp option in an initial SYN segment (i.e., segment containing a SYN bit and no ACK bit), and may send a TSopt in other segments only if it received a TSopt in the initial SYN segment for the connection.

]]> By: Anant Shrivastava https://www.exploresecurity.com/testing-for-tcp-ip-timestamps/#comment-2464 Anant Shrivastava Tue, 28 Oct 2014 06:48:51 +0000 http://www.exploresecurity.com/?p=261#comment-2464 or we can do

hping3 -S -c 2 -p –tcp-timestamp

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