4.3BSD-Reno/share/man/cat4/icmp.0

ICMP(4)                       1990			  ICMP(4)



NNAAMMEE
     icmp - Internet Control Message Protocol

SSYYNNOOPPSSIISS
     ##iinncclluuddee <<ssyyss//ssoocckkeett..hh>>
     ##iinncclluuddee <<nneettiinneett//iinn..hh>>

     ss == ssoocckkeett((AAFF__IINNEETT,, SSOOCCKK__RRAAWW,, pprroottoo));;

DDEESSCCRRIIPPTTIIOONN
     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 _p_r_o_t_o parameter to the socket call to create
     an ICMP socket is obtained from _g_e_t_p_r_o_t_o_b_y_n_a_m_e(3).  ICMP
     sockets are connectionless, and are normally used with the
     _s_e_n_d_t_o and _r_e_c_v_f_r_o_m calls, though the _c_o_n_n_e_c_t(2) call may
     also be used to fix the destination for future packets (in
     which case the _r_e_a_d(2) or _r_e_c_v(2) and _w_r_i_t_e(2) or _s_e_n_d(2)
     system calls may be used).

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

DDIIAAGGNNOOSSTTIICCSS
     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 destination
		    address specified and the socket is already
		    connected;

     [ENOTCONN]     when trying to send a datagram, but no desti-
		    nation 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.

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






Printed 7/27/90               June				1