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TCP sequence number (tcpseq)

Description

Returns the sequence number of a TCP segment. This value has a dual role:

  • If the SYN flag is set (1) → initial sequence number

  • If the SYN flag is clear (0) → accumulated sequence number of the first data byte of the segment

How does it work in the search window?

Select Create field in the search window toolbar, then select the TCP sequence number operation. You need to specify one argument:

Argument

Data type

Argument

Data type

Packet mandatory

packet

The data type of the values in the new field is integer.

How does it work in LINQ?

Use the operator select... as...  and add the operation syntax to create the new field. This is the syntax for the TCP sequence number operation:

  • tcpseq(packet)

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