inet.7f (2010 09)

inet(7F) inet(7F)

NAME

inet - Internet protocol family

SYNOPSIS

#include <sys/types.h>

#include <netinet/in.h>

DESCRIPTION

The internet protocol family is a collection of protocols layered on top of the Internet Protocol (IP) net-

work layer, which utilizes the internet address format. The internet family supports the SOCK_STREAM

and SOCK_DGRAM socket types.

Addressing

Internet addresses are four byte entities. The include ﬁle <

netinet/in.h> deﬁnes this address as the

structure

struct in_addr.

Sockets bound to the internet protocol family utilize an addressing structure called

struct

sockaddr_in. Pointers to this structure can be used in system calls wherever they ask for a pointer to

a struct sockaddr.

There are three ﬁelds of interest within this structure. The ﬁrst is

sin_family, which must be set to

AF_INET. The next is

sin_port, which speciﬁes the port number to be used on the desired host. The

third is sin_addr, which is of type struct in_addr, and speciﬁes the address of the desired host.

Protocols

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

SOCK_STREAM socket type while UDP is used to support the SOCK_DGRAM 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 time.

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.

AUTHOR

inet was developed by the University of California, Berkeley.

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inet(7F) inet(7F) NAME inet - Internet protocol family SYNOPSIS #include #include DESCRIPTION The internet protocol family is a collection of protocols layered on top of the Internet Protocol (IP) network layer, which utilizes the internet address format. The internet family supports the SOCK_STREAM and SOCK_DGRAM socket types. Addressing Internet addresses are four byte entities. The include file defines this address as the structure struct in_addr.
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(Notes) A (Notes) iA 2 Hewlett-Packard Company −1− HP-UX 11i Version 3: September 2010