TCP/IP header fields

The file fields.tc defines the fields used in the headers of some of the most common protocols in the TCP/IP protocol suite.^2.3

Note that the same names are also used when constructing packets with tcsim, see section 6.5.1.

In the following sections, we describe header structures as follows:

$$\begin{tabular}{l\vert cccccccccccccccccccccccccccccccc\vert... ...e{2-33} \multicolumn{33}{l}{{\tt foo\_data}} \\ \end{tabular}$$

foo_hdr marks the beginning of the header of the hypothetical protocol ``foo''. foo_field1 to foo_field3 are simply header fields. If ``foo'' contains an optional part, foo_options points to it. Finally, if there is data following the ``foo'' header, foo_data points there. If a ``foo'' header was typically followed by a header of a protocol called ``bar'', bar_hdr would be equivalent to foo_data.