icmp(4) [netbsd man page]

ICMP(4) 						   BSD Kernel Interfaces Manual 						   ICMP(4)

NAME

     icmp -- Internet Control Message Protocol

SYNOPSIS

     #include <sys/socket.h>
     #include <netinet/in.h>

     int
     socket(AF_INET, SOCK_RAW, proto);

DESCRIPTION

     ICMP is the error and control message protocol used by IP and the Internet protocol family.  It may be accessed through a ``raw socket'' for
     network monitoring and diagnostic functions.  The proto parameter to the socket call to create an ICMP socket is obtained from
     getprotobyname(3).  ICMP sockets are connectionless, and are normally used with the sendto(2) and recvfrom(2) calls, though the connect(2)
     call may also be used to fix the destination for future packets (in which case the read(2) or recv(2) and write(2) or send(2) system calls
     may be used).

     Outgoing packets automatically have an IP header prepended to them (based on the destination address).  Incoming packets are received with
     the IP header and options intact.

DIAGNOSTICS

     A socket operation may fail with one of the following errors returned:

     [EISCONN]	      when trying to establish a connection on a socket which already has one, or when trying to send a datagram with the destina-
		      tion address specified and the socket is already connected;

     [ENOTCONN]       when trying to send a datagram, but no destination address is specified, and the socket hasn't been connected;

     [ENOBUFS]	      when the system runs out of memory for an internal data structure;

     [EADDRNOTAVAIL]  when an attempt is made to create a socket with a network address for which no network interface exists.

SEE ALSO

     recv(2), send(2), inet(4), intro(4), ip(4)

     Internet Control Message Protocol, RFC, 792, September 1981.

     Requirements for Internet Hosts -- Communication Layers, RFC, 1122, October 1989.

HISTORY

     The icmp protocol appeared in 4.3BSD.

BSD
								   June 5, 1993 							       BSD

icmp(7) 						 Miscellaneous Information Manual						   icmp(7)

NAME

       icmp - Internet Control Message Protocol

SYNOPSIS

       #include <sys/socket.h> #include <netinet/in.h>

       The following is the socket call for sockets using the IPv4 address format:

       s = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);

       The following is the socket call for sockets using the IPv6 address format: s = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);

DESCRIPTION

       The  Internet Control Message Protocol (ICMP) is the error and control message protocol used by the Internet Protocol (IP) and the Internet
       Protocol family.  It may be accessed through a raw socket for network monitoring and diagnostic functions.  ICMP  sockets  are  connection-
       less, and are normally used with the sendto() and recvfrom() functions.	The connect() function may also be used to fix the destination for
       future packets, in which case the read() or recv() and write() or send() functions may be used.

       Outgoing packets automatically have an IP header prepended to them (based on the destination address).  Incoming packets are received  with
       the IP header and options intact.

ERRORS

       If a socket operation fails, errno may be set to one of the following values: The socket is already connected.  This error occurs when try-
       ing to establish connection on a socket or when trying to send a datagram with the destination address specified.  The destination  address
       of  a  datagram was not specified, and the socket has not been connected.  The system ran out of memory for an internal data structure.	An
       attempt was made to create a socket with a network address for which no network interface exists.

RELATED INFORMATION

       Functions: send(2), recv(2)

       Files: netintro(7), inet(7), ip(7)

       RFC 792, "Internet Control Message Protocol"

       RFC 2463, "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6)" delim off

																	   icmp(7)