inet(7F)inet(7F)NAMEinet - Internet protocol family
The internet protocol family is a collection of protocols layered on
top of the (IP) network layer, which utilizes the internet address for‐
mat. The internet family supports the SOCK_STREAM and SOCK_DGRAM
Internet addresses are four byte entities. The include file defines
this address as the structure
Sockets bound to the internet protocol family utilize an addressing
structure called Pointers to this structure can be used in system calls
wherever they ask for a pointer to a
There are three fields of interest within this structure. The first is
which must be set to AF_INET. The next is which specifies the port
number to be used on the desired host. The third is which is of type
and specifies the address of the desired host.
The internet protocol family is comprised of the IP network protocol,
Internet Control Message Protocol (ICMP), Transmission Control Protocol
(TCP), and User Datagram Protocol (UDP). TCP is used to support the
socket type while UDP is used to support the socket type. The ICMP
message protocol and IP network protocol are not directly accessible.
The local port address is selected from independent domains for TCP and
UDP sockets. This means that creating a TCP socket and binding it to
local port number 10000, for example, does not interfere with creating
a UDP socket and also binding it to local port number 10000 at the same
Port numbers in the range 1-1023 inclusive are reserved for use by the
super-user only. Attempts to bind to port numbers in this range by
non-super-users fail and result in an error returned.
was developed by the University of California, Berkeley.
SEE ALSOtcp(7P), udp(7P).