The <tt>netinet</tt> directory holds the code for the Internet network
protocols used in FreeBSD: TCP, IP, ICMP, ARP.<p>

The 4.3BSD Internals book by Leffler, McKusick, Karels and Quarterman
covers <tt>netinet</tt> in:

<dl>
<dt> <b>Chapter 12</b>, pp 343-389 <i>Network Protocols</i>.
</dl>
<p>