icmp(4p) [ultrix man page]

icmp(4p)																  icmp(4p)

Name
       icmp - Internet Control Message Protocol

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

       s = socket(AF_INET, SOCK_RAW, proto);

Description
       The ICMP is the error and control message protocol used by the Internet Protocol (IP) transport layer and the Internet protocol family.	It
       can be accessed through a ``raw socket'' for network monitoring and diagnostic functions.  The proto argument to the socket call to  create
       an  ICMP  socket is obtained from the routine.  ICMP sockets are connectionless, and are normally used with the and system calls.  The call
       can also be used to fix the destination for future packets (in which case the or and or system calls can then 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
       On failure, a socket operation returns any of the following errors:

       [EISCONN]      Tried  to  establish a connection on a socket that already has one, or tried to send a datagram with the destination address
		      specified and the socket was already connected.

       [ENOTCONN]     Tried to send a datagram, but no destination address was specified, and the socket has not connected.

       [ENOBUFS]      The system ran out of memory for an internal data structure.

       [EADDRNOTAVAIL]
		      An attempt was made to create a socket with a network address for which no network interface exists.

See Also
       inet(4f), intro(4n), ip(4p)

																	  icmp(4p)

icmp(7P)							     Protocols								  icmp(7P)

NAME

       icmp, ICMP - Internet Control Message Protocol

SYNOPSIS

       #include <sys/socket.h>
       #include <netinet/in.h>
       #include <netinet/ip_icmp.h>
       s = socket(AF_INET, SOCK_RAW, proto);
       t = t_open("/dev/icmp", O_RDWR);

DESCRIPTION

       ICMP  is  the error and control message protocol used by the Internet protocol family. It is used by the kernel to handle and report errors
       in protocol processing. It may also be accessed by programs using the socket interface or the Transport Level Interface (TLI)  for  network
       monitoring  and	diagnostic functions. When used with the socket interface, a "raw socket" type is used. The protocol number for ICMP, used
       in the proto parameter to the socket call, can be obtained from getprotobyname(3SOCKET). ICMP file descriptors and sockets are  connection-
       less, and are normally used with the t_sndudata / t_rcvudata and the sendto() / recvfrom() calls.

       Outgoing  packets automatically have an Internet Protocol (IP) header prepended to them. Incoming packets are provided to the user with the
       IP header and options intact.

       ICMP is an datagram protocol layered above IP. It is used internally by the protcol code for various purposes including routing, fault iso-
       lation, and congestion control. Receipt of an ICMP "redirect" message will add a new entry in the routing table, or modify an existing one.
       ICMP messages are routinely sent by the protocol code. Received ICMP messages may be reflected back to users of higher-level protocols such
       as  TCP or UDP as error returns from system calls. A copy of all ICMP message received by the system is provided to every holder of an open
       ICMP socket or TLI descriptor.

SEE ALSO

       getprotobyname(3SOCKET), recv(3SOCKET), send(3SOCKET), t_rcvudata(3NSL), t_sndudata(3NSL), inet(7P), ip(7P), routing(7P)

       Postel, Jon, Internet Control Message Protocol -- DARPA Internet Program Protocol Specification, RFC 792, Network Information  Center,  SRI
       International, Menlo Park, Calif., September 1981.

DIAGNOSTICS

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

       EISCONN		An  attempt  was  made to establish a connection on a socket which already has one, or when trying to send a datagram with
			the destination address specified and the socket is already connected.

       ENOTCONN 	An attempt was made to send a datagram, but no destination address is specified, and the socket has not been connected.

       ENOBUFS		The system ran out of memory for an internal data structure.

       EADDRNOTAVAIL	An attempt was made to create a socket with a network address for which no network interface exists.

NOTES

       Replies to ICMP "echo" messages which are source routed are not sent back using inverted source routes, but rather go back through the nor-
       mal routing mechanisms.

SunOS 5.11							    3 Jul 1990								  icmp(7P)