netlog(1) [mojave man page]

netlog(1)						    BSD General Commands Manual 						 netlog(1)

NAME

     netlog -- Log summary of every UDP and TCP socket when the socket is closed.

SYNOPSIS

     netlog [-v] [-i interval] [-I iterations] [-t type] [-p process-name|pid] [-c] [-z]

DESCRIPTION

     The netlog program logs a summary for each TCP and UDP socket when the socket is closed. A header is printed once. The row items are sepa-
     rated by spaces.  Address to hostname lookups are not performed. Sockets that do not send or receive any data are not listed unless the -z
     option is specified.

OPTIONS

     A list of flags and their descriptions:

     -v       Verbose output

     -i interval
	      Report socket statistics periodically

     -I iterations
	      Used in combination with -i, will make netlog exit after the specified number of iterations.

     -t type  Specify the type of interface. By default, all interfaces will be monitored.  Multiple interface types may be specified.	The fol-
	      lowing types are supported:

	      wifi     WiFi interfaces

	      wired    Wired interfaces

	      loopback
		       Loopback interfaces

	      awdl     Apple Wireless Direct Link interfaces

	      expensive
		       Interfaces marked as "expensive", for example via hotspot

	      undefined
		       Cases where the underlying socket is not associated with an interface

	      external
		       The combination of all defined non-loopback interfaces.

     -p process-name|pid
	      Select a process for display.  A numeric argument identifies a process by its pid.  Alternatively a process name may be given, in
	      which case all processes with that name will be displayed.  The name must be an exact match for the name displayed by netlog, which
	      may require that the name be truncated, for example launchd.develop instead of launchd.development.  This option may be repeated to
	      select multiple processes.

     -c       Print details in comma-separated values (CSV) form.

     -z       Print details even if there was no data transfer on the socket

Darwin								   May 31, 2019 							    Darwin

UDP(7P) 																   UDP(7P)

NAME

       UDP - Internet User Datagram Protocol

SYNOPSIS

DESCRIPTION

       UDP  is	a  simple, unreliable datagram protocol used to support the socket type for the internet protocol family.  UDP sockets are connec-
       tionless, and are normally used with the and calls (see send(2) and recv(2).  The call can also be used to simulate a connection (see  con-
       nect(2).   When	used  in  this	manner,  it fixes the destination for future transmitted packets (in which case the or system calls can be
       used), as well as designating the source from which packets are received.  The and calls can be used at any time if the source of the  mes-
       sage is unimportant.

       UDP  address  formats are identical to those used by TCP.  In particular, UDP requires a port identifier in addition to the normal Internet
       address format.	Note that the UDP port domain is separate from the TCP port domain (in other words, a UDP port cannot be  connected  to  a
       TCP port).

       The  default  send  buffer  size for UDP sockets is 65535 bytes.  The default receive buffer size for UDP sockets is 2147483647 bytes.  The
       send and receive buffer sizes for UDP sockets can be set by using the and options of the system call or the and options of the system call.
       The maximum size for these buffers is 2147483647 bytes. The maximum receive buffer size may be lowered using the parameter

       The  maximum  message size for a UDP datagram socket is limited by the lesser of the maximum size of an IP datagram and the size of the UDP
       datagram socket buffer.	The maximum size of an IP datagram limits the maximum message size of a UDP message to	65507  bytes.	Therefore,
       using  the  maximum  socket buffer size will allow multiple maximum-sized messages to be placed on the send queue.  The default inbound and
       outbound message size limit for a UDP datagram socket is 65535 bytes.

       The maximum message size for a UDP broadcast is limited by the MTU size of the underlying link.

ERRORS

       One of the following errors may be returned in if a socket operation fails.  For a more detailed list of errors, see the man pages for spe-
       cific system calls.

	      [EISCONN] 	    Attempt to send a datagram with the destination address specified, when the socket is already connected.

	      [ENOBUFS] 	    No buffer space is available for an internal data structure.

	      [EADDRINUSE]	    Attempt to create a socket with a port which has already been allocated.

	      [EADDRNOTAVAIL]	    Attempt to create a socket with a network address for which no network interface exists.

AUTHOR

       The socket interfaces to UDP were developed by the University of California, Berkeley.

SEE ALSO

       ndd(1M).  getsockopt(2), recv(2), send(2), socket(2), t_open(3), t_optmgmt(3) inet(7F), socket(7),

       RFC 768	      User Datagram Protocol
       RFC 1122       Requirements for Internet hosts

																	   UDP(7P)